I'm new as well, Bay Area also! I agree KBDfans has some decent options, tada68, etc. I assume you know of what Ducky, Akko, maybe Vortexgear have on offer already. If you're really looking to assemble a bunch of totally disparate parts, it would be a good idea to go with a standard case size which lots of different styles of parts are made for. Like, there are PCBs that can fit up to like a 75% into the dimensions of a pretty standers 60% case.
I'm probably not the best one to be giving out advice, but I have been doing a lot of research and have a growing list of different vendor sites and such in my bookmarks, hope something in there helps.