First, by DB on flash, I just meant storing the actual DB files, logs, etc on an SSD. If you have an NVME SSD, all on one drive is probably your best bet. If you are running SATA, you may pick up a bit of speed having tempDB on its own SSD, but we're fairly deep in the weeds here. If you're getting poor performance on a 10GB DB with 2-3 connections on SSD with 32+GB of RAM and 8 cores, I blame the devs for any lack of performance their, assuming good baseline SQL config. I haven't played online for a long time though, so this is adapting just enough to be dangerous SQL knowledge from my day job.
With the right case, ITX shouldn't be a problem for overclocking, assuming high quality boards are made and not just bottom dollar junk. I go to LANs 3-4x a year and don't anticipate going back to a cross-fire or SLI setup (my current rig started with 2x7970s, went to a 980 for VR, currently on a 1080 because of charity raffle run-good).
I'm mainly looking at the case below which has room for a 2x120 closed loop liquid CPU cooler. Bear in mind that current Ryzen products are going to top out at 3.8-4.1 GHz. I don't have a problem with AMD leaving little OC headroom on the table, they're playing from behind and need to bring as much as they can stock.
http://www.caselabs-store.com/bullet...-customizable/
A VM (assuming cloud based) with 128GB seem like it would be pretty pricey. IIRC Azure SKUs with than much RAM run a few kilobucks a month, which would add up even running part time. I'm not familiar with Google or AWS pricing for similar.