OK, so here's my thing - I have the below setup, and I want to upgrade my ram, and upgrade my 32bit Windows 7 to 64bit. I've been looking at some 4gb (2x2) sets, but I am wondering whether its best to go with the best set regardless, or to try and get something that I can add into my current set to bring it up to 6gb. Any recommendations of the best way to go, and especially recommendations on the memory to go for (if adding memory to the existing is recommended, I could really do with advice on the best set to go for, in order to best match ram specs etc.)
Intel Dual Core E7200 2.53GHz
EVGA GeForce 8800GT Superclocked Edition
2GB Corsair XMS2 800Mhz (2X1gb)
Thermaltake Purepower 500W PSU
250gb Seagate Barracuda 7200 HD (this is plenty for me as I have docs, media etc. stored on a NAS)
NZXT Alpha CS-NT-ALP-WOW Tower
Would really appreciate any advice before I pull the trigger and order something.