AMD and thermal Grease:
Use of ANY thermal grease besides G749 voids the warranty; G749 is only to be used short term, for testing only. The only other approved method is Phase Change Material, PCM this is the pad that comes with the stock heat sink. Nothing else... however, OEM chips come with no warranty from AMD, so the only warranty you have is a 30 day replacement warranty from newegg. Personally I void a lot of warranties, but if you are concerned about it, run it with the stock cooling for a few days, put it through its paces, and if it passes, upgrade the heat sink and thermal grease so it stays nice and cool. I’ve used artic silver for years and never had trouble, just remember that it is conductive, so don’t get it near the wires use a very thin coat on the chip only, less is more.
As for a case, if you get a cheep case, it will be noisy; you want to spend at least $50 to $75 for a nice roomy aluminum case. I just built a system in a Cooler Master Mystique 631 for a client, its nice, roomy and quiet, 2 large 120 mm fans and a side vent.
http://www.newegg.com/Product/Produc...82E16811119107