|"can you recommend me a casing?"|
Casings are used for making sausages & hotdogs, I think you mean "case"? It's difficult to recommend a case because everyone has their own opinion of what looks good. Plus we have no idea of how much you're willing to spend. Personally I'm not a fan of cases that put the power supply at the bottom rather than the top, but that's your decision.
The Problem of Bottom-Mounted Power
And even though I posted the above, here's a very popular bottom mount gaming case at newegg:
Also, get a good quality, brand name power supply. It should be at least 500W, have a single high amperage +12v rail, active PFC, 80 Plus efficient, good warranty. You're spending a lot of money on your other hardware, don't cut corners on the power supply.