Im confused, whats wrong with that case? Why cant you use the USB ports? And why do you have an APU and a 7770? Im pretty sure that card is not able to do a hybrid CFX with the APUs graphics. I know very little about APUs but the most I have heard anyone doing a hybrid CFX with for an APU is a 6670. Why not go with a comparably priced AM3+ CPU?
Take a look at this CPU and Motherboard. The motherboard is a bit more expensive than you have been looking at but well worth the difference in quality in the end.