I suffer from impaction occasionally and used to irrigate with 2% hydrogen peroxide. The H2O2 reacts with the wax and helps break it up. It is one of the strangest sensations though, bubbles forming and popping en masse inside of your ear canal. Eventually I bought an ear cleaning otoscope and scoop out the wax manually every few months.

That sounds like a fun experimentation platform. Power shouldn’t be a problem except for the bill, the PSUs are meant to be redundant rather than for combined output. You probably won’t draw more than 300 watts most of the time. The drive controller probably has staggered spin-up to prevent over current conditions. The bigger factor in my experience is the noise, expect a jet engine during boot and a dull roar the rest of the time. SuperMicro boards often allow you to set the fans lower, but the PSUs will be loud all the time. If I were you, I’d install TrueNAS or ProxMox and play around with it. You may be able to triage the issues. You may need to set the drive controllers to HBA mode or flash an HBA firmware to them. It’s probably not worth running long term with SandyBridge, power to performance is pretty bad.