4 GB of RAM is excellent and the 550-Watt PSU is a great choice. I don't know anything about AMD's processors because I'm now an Intel guy, but 2.2 GHz is decent/good and I'm going to assume it's a dual-core processor, so it's pretty awesome.
What exactly are you wanting to do with your computer? You say you want a super powerful computer but what for? Gaming? What game do you have in mind that you'd like to be able to play at very high/max settings?
Processor is actually a quad core.
And I made a mistake, I meant to say I don't need anything super powerful. Basically I want a computer that can run most of the games out there at mid-high settings at 1680x1050. Games like Stalker: Clear Sky, Far Cry 2, Red Alert 2, maybe Crysis, L4D, and ultimately HL2: Episode 3
A while back I was looking at a Geforce 8800 GT 1GB card. Had a good price on it and it. Hows that sound?