I couldn't tell you on the mobo, I'd have to read about it.
The FX55 is currently the best processor in the world as far as I'm concerned. Most Intel enthusiasts would say otherwise, but what do they know anyway. Of course I'm talking about just home PCs and not xeons and whatnot since I dont know shit about those. Although I would wait to buy it until they release the FX57 because the price will go down.
Yeah, I must have gotten confused because you said "I am thinking of 2ea 1GB for less then $200". Although if you are planning on getting 2 gigs, I say you get 2 1 gig sticks and run them in dual channel. If you want this computer to run for a few years as you said you will at LEAST have to upgrade your memory and you don't want to waste all your slots with 512 sticks you'll just end up having to get rid of in a few years when you want to upgrade.
For a v-card I suggest the 6800 Ultra from either eVGA or BFG. I have the eVGA and it runs fan-fuckin-tastic. BFG is a GREAT company and their cards come overclocked with a warranty from the factory. If you have a problem with the card they'll just send you a brand new one to replace yours. The BFG is a bit more than the eVGA but if you have the money, I say get the BFG.
WHY the Ultra? Well it's just plain better
Ap3 Tit could probably explain the technical shit as to why, but all I know is I had both and the Ultra just seems a wee bit faster in my opinion.