I don't think this is relevant or even necessarily accurate. It seems like the OP is more concerned as to which will be more performant, not power consumption. In any case, though the 3080 Ti is a more power hungry card, the A2000 may run hotter due to its smaller cooler.

Hi, welcome to Hardware Recs! There's a lot of range in terms of GPU compute, and different cards will be suited for different kinds of CUDA. Are the simulations you're doing open source/do you have sample benchmarks available? What bit depth do you run at?

Is there a reason you're tied to hardware RAID over software RAID? It'll almost certainly be easier and cheaper (and likely more performant) to run software RAID.

Hi A. Bear, welcome to Hardware Recs! The first two you've found look perfect, I'd say get one of each of those. You may also want one of these (or Swedish equivalent) for the front USB 2.0 ports on the case; it looks like you've got enough connectors on the motherboard that you should have no trouble.

Hi AmusedFigure, welcome to Hardware Recs! Couple questions: 1. Where is the music that's being played coming from? Is it stored on the MP3 jukebox/phone, or is it streamed via Spotify/Apple Music/et al? 2. Would it be better if the headphones (or another device which remains on the user's person) is able to always play the music, that way the music doesn't stop playing if there's a physical separation? It could still be remotely controllable from the phone, but it'd prevent interruptions if there's a separation.