Id stay away from used vid cards myself, unless your getting them really cheap, which you are not. 5850's were going for just under $200 new, and you can get a 6870 for just under $200. Well at least in the US and australia the pricing is like that. Shop around, rather than just going to your local pc store. 8gb is not necessary, you could put 4 in and always add another 4gb later if you dont think its enough. If your looking at a gaming pc stay away from 6 core CPU's. Some games run worse on them while 99.9% of games see no benefit from more than 4 cores. Save some money on the CPU, get a pII 965 and get the 6950.