you can go for the 8800 gts which is available for around 300$ and is of course less powerful than the gtx. An alienware system with almost the same options is gonna cost no less than 4000$ I myself use OCZ memory and I know many friends who use it and they never had a problem. They are good for overclocking too and also a bit cheaper than the corsair modules. overclocking to 3.6GHz is good to hear but practically its not really achievable without water cooling. the 6600 can be easily oc'ed to 3.2GHz with air cooling only which is a fairly reasonable overclock.