If ure not going for 4K gaming and dont need ray tracing and dlss, this is ok. What is the cpu?
I'll tell you this is overpriced and might as well get from SLS.
6900XT is great for gaming but price is hardly that high. Maximum around $2.2k for a full system build.
Mobo: MSI MAG is the lower tier for MSI gaming boards, below MPG and MEG. X570 is unnecessary unless you need high PCIe bandwidth, like I did when I ran 2 GPUs on PCIe 4.0x8. Even then, not all X570 boards give x8 speed to the second PCIe slot, some only give x4 or worse, 3.0x4, which means it's an X570 board that doesn't maximize the chipset potential. My Gigabyte X570 Aorus Master is an almost top tier X570 board and costs only $500, this MAG Tomahawk I think is in the $300 territory.
RAM: okay, RAM is expensive now, 32GB this variant maybe worth about $270 - $280
SSD: better check whether it's the lower tier PCIe 4.0 SSD or the higher tier one. Lower tiers have a sequential read speed around 4500 - 5000MB/s, which in real life is not much difference from the best Gen 3 drives, or even something like the WD Blue SN550 with a sequential read of 2400MB/s. Only the higher tier Gen 4 which have up to 7000MB/s are worth the price premium now. Aftershock have this variant in their lineup.
PSU: RM850 should be an 80plus gold, probably worth around $200 - $220 new.
AIO: okay, 360mm quite exp, and if you want to buy local then pay the premium. But yes, what CPU? Anything lower than 105W TDP probably won't benefit from it. I.e. unless you are running Zen 2 3900X and above or Zen 3 5800X and above, this is overkill. I run my 5900X on a 240mm and it still kills benchmarks. CPU usually runs at lower steady clocks when gaming vs. benchmarking too, so it should require even less cooling. Ryzen is well known for being energy efficient so make sure you are not paying for what you don't need.
If you're really willing to pay $5k, honestly, do yourself a favor and go to Aftershock or SLS and get yourself a system with a RTX3090. GPUs are the most critical component now and you'll thank yourself for getting a 3090 over a 6900XT. If not, get a 3080 system from the same providers and save yourself a few hundred bucks, and still get superb gaming performance.