A GT 430..... down grade the CPU to a Athlon X3 450 and get yourself a GTX 460 (SE or 768MB) instead. A GT 430 is pretty much darn near pointless if you have integrated graphics.
For a case, I suggest looking for one in a trash can. Cooling.. depends.
What are you doing with this Box?
Downgrade to the Athlon II X3 450 Rana and get yourself a HD 6850, uses alot less power for equal performance, can usually be found cheaper than the HD 6850 also.