If you don't really need a discrete graphics card then just wait a couple more weeks and buy AMD's Ryzen 4000 desktop APUs with a potent integrated one. Ryzen 3 4200g will have 4 coress & 8 threads, Ryzen 5 4400G - 6/12, Ryzen 7 4700G - 8/16. As for the case you can go even smaller and buy...