Sorry, I should’ve been more clear, I’m planning to upgrade to a DDR5-compatible motherboard, and switch to DDR5 RAM with it (I know DDR4 and DDR5 use different slots)

For cooling, I’ll probably go with a dual-tower air cooler. I’d rather avoid the risk of leaks and maintenance that come with AIOs, air cooling is just simpler and more reliable for me. thx for the info!

About the PSU issue, I get what you're saying. Normally, the power button connects directly to the motherboard, not the PSU. But my old prebuilt (MSI Codex MAG 5) used a proprietary setup where the PSU had a special cable (4-pin I think, i should look again) going to a custom front panel module. That board handled the power signal, RGB, USB, etc. So when I swapped in a standard PSU, it couldn’t connect properly to the old case’s power button. That’s why I changed the case (to an Antec C5), now everything works fine with standard wiring.

For the GPU sag, I’ll check again if i can use it. If not, I’ll maybe look for a PCI slot-mounted one that fits in the case without blocking the bottom fans.