For the case just about any will do, as long as it's microATX. Any bigger would likely be wasted space with the size of your motherboard, and anything smaller would defeat the purpose. As far as the powersupply goes, I find it hard to recommend anything but the best because I've been burned on cheap PSUs before. So I would say: at least 500watts, 80+ Bronze or better, and made by Antec, Corsair, or Seasonic. For the graphics card, I have to ask- Do you ever think you'll get a higher res monitor? That pretty well dictates what card you should get.
Didn't see your last post. If you switch your case, you're basically going to have to get a new powersupply with it because your current one is a weird form factor that wouldn't fit.