I stick to ASUS, and Supermicro for motherboards that do work. I have an old low end gigabyte mATX board that was part of a media PC back in the day, it's fine, but not something I'd crunch with full-time. In general for crunching motherboards I like to stay with server and workstation class hardware. it's always very reliable, robust, and doesnt have the nonsense they put into consumer level boards.

For GPUs I overwhelmingly stick to EVGA. they have been the most reliable and i feel they have a closer relationship with nvidia than some of the other vendors. I've done a handful of RMAs (I have a lot of GPUs, so it's inevitable) and they have been pretty smooth. I generally don't like gigabyte/msi and others nvidia GPUs unless I need a very specific size/config that forces me out of an EVGA option. for example, my 7x RTX 2080 system that's watercooled single slot (all 7 cards plugging directly to motherboard), I couldn't use EVGA because they didnt have an RTX 2080 that was able to be single slot (due to the DP on the second slot), so I went with ASUS cards instead. and while it's been working OK, I'm still weary about it.

---

I stick to ASUS, and Supermicro for motherboards that do work. I have an old low end gigabyte mATX board that was part of a media PC back in the day, it's fine, but not something I'd crunch with full-time. In general for crunching motherboards I like to stay with server and workstation class hardware. it's always very reliable, robust, and doesnt have the nonsense they put into consumer level boards.

For GPUs I overwhelmingly stick to EVGA. they have been the most reliable and i feel they have a closer relationship with nvidia than some of the other vendors. I've done a handful of RMAs (I have a lot of GPUs, so it's inevitable) and they have been pretty smooth. I generally don't like gigabyte/msi and others nvidia GPUs unless I need a very specific size/config that forces me out of an EVGA option. for example, my 7x RTX 2080 system that's watercooled single slot (all 7 cards plugging directly to motherboard), I couldn't use EVGA because they didnt have an RTX 2080 that was able to be single slot (due to the DP on the second slot), so I went with ASUS cards instead. and while it's been working OK, I'm still weary about it.

Pardon my french, but EVGA sells the biggest CRAP I've ever had!
Every one of my EVGA GPUs broke, or got returned.
Even EVGA PSUs being buggy, or burned out!

I find EVGA to be cheap Chinese products, that just have great customer service department in USA.
However, I got tired of returning my products. All in all, I've had a good 10 GPUs (there still are about 3 that work, but 2060s that I don't crunch on, they're too slow. Even their 2080 Ti failed with a 1350Mhz lock on). and I've had 6 PSUs from them, and all but 2 failed.
Since I can keep the original box, they send me a new box and cables back; which is nice.
But after owning 6 spare EVGA boxes and cables, and paying a $50 shipping fee with each return, I got tired of them.

Even my Zotac 2060 AMP, which I absolutely abused, and I removed the fairing, was regularly squeezed in spaces too small for it; got regular fan swaps; and it still works.

Every GPU is different, but my experience with EVGA, ASUS, MSI all weren't very good!
Most of them failed through static, from moving from 1 server to another. Some were DOA.

Though I got to give it to them; their CS is impeccable.
Compared to ASUS, they would charge me $200 (+ shipping) to fix a blade of a fan that broke off one of their Rog Strix GPUs. Initially I just wanted a spare fan. But told them that 2 minutes with crazy glue was a better option than $200 minus the time wasted.
The ROG strix GPU still works, but no aftermarket fans fit them.

But asus really F#-'d it up, when another one of my GPUs stopped working. Was returned. And they said it had 'customer damage'.
From the photos (and after they sent it back to me) it was clear some of the caps leaked, and caused the GPU to fail. Not my fault. But they didn't want to fix it in warranty, claiming I had spilled a chemical inside the GPU. INSIDE! The warranty sticker was still on there! There's no way I'd be able to spill anything between the heat sink and board!

They requested $700 to fix. Then they just returned it without even waiting for my 2 day delayed response!
I was so steaming mad, that I decided I would never give ASUS any more of my business!
Their Laptops are the best, but their CS is non-existent!
And their GPUs aren't as reliable as the Gigabytes. I only have had 1 issue with the 10 RTX Gigabyte GPUs I'm currently running, and that was the HDMI port failed, after too much plugging/unplugging.
Thankfully I still own a DVI to HDMI adaptor.

sounds like you got extremely unlucky or misused the products (too much plugging on the HDMI port? come on now) and/or had outside factors kill your GPUs (failing/out of spec PSU, defective motherboard, etc). I've had well over 50 EVGA GPUs pass through my hands in the last few years, across the entire product stack from low end to high end. and I have the exact opposite experience. I've RMA'd less than 5 of them. my "big" system now, is running TEN EVGA RTX 2070 cards, they were all bought already used. and all of them have been running for over a year on SETI/Einstein/GPUGRID with almost no downtime and they are still chugging. I currently have 18 or 19 EVGA GPUs (2070-2080ti) running. and 7 ASUS RTX 2080s on the watercooled system. I had mediocre experience with ASUS AMD GPUs though. (2 out of 6 RX 570s I had a few years ago ended up needing RMA).

EVERY nvidia/AMD GPU is made in some part in China. EVGA is an American company, they buy the GPUs from nvidia (like all nvidia AIBs do...), who manufactures in Taiwan, and GPU assembly happens in several factories in China and Taiwan using parts sourced from several other countries like Japan and Korea, and some final assembly in the US. this is the same for nearly ALL AMD and nvidia GPU manufacturers. if you consider EVGA to be "cheap Chinese products", then all GPUs are cheap Chinese products because they all use the same factories in China lol.

Gigabyte is based in Taiwan, ASUS is based in Taiwan. Zotac is based in Hong Kong (also China, btw). they all manufacture in China.

I've only ever had one EVGA PSU. the one powering my 7x RTX 2080 system. EVGA 1600 P2. running 1300-1400W 24/7 without a hitch. it was also bought used and not new and always gets rave reviews from the PSU gurus.

---

If you want to overclock Ryzen, you need to study how by reading the overclocking forums where the OC masters hang out. Tons of experience and knowledge can be gleaned by simply reading.
OCN is my goto.

You can use the Advanced AMD Overclocking section of the BIOS to change the PPT, EDC and TDC limits. That is the best way to achieve the highest clocks at the desired power limit level
https://www.overclock.net/forum/13-amd-general/1741052-edc-1-pbo-turbo-boost.html

Most AIO's are woefully weak in coolant flow and capacity. They just don't move enough water and fast enough through the coldplate to remove the heat from OC'd Ryzens, even with a 360 radiator.
If you want high clocks you need to keep the cpu cool with adequate cooling. That is easiest to achieve with custom cooling.

There are higher quality AIOs that bridge the performance of consumer AIOs and custom cooling with better performance than the mass-market consumer AIO brands. Look at Alphacool Eisbaer 360 for example, Swiftech Drive X3 or EK AIO 360.