I bought a Codegen V2 500mm the other day and it worked out great for my needs. It's got 9x3.5" bays and can fit a regular ATX motherboard. In the attached pictures, I've currently got a mATX motherboard. The fan it comes with isn't great and has a molex connector so I'd recommend purchasing a separate one. I've also got 2x80mm fans on order for the back.
Please forgive the fact that it's plugged into a Google Wifi router and is sitting in my son's room, this isn't its final place - I'm looking for a small rack (9-12U) that will just fit this case and isn't too much longer - any suggestions?
Edit: the parts originally started life in an old rig and evolved into the slight mess you see here. I'll be ordering some better components when I work out which ones I need.