Hi, im looking to build a new computer. But need some help. As of now, i really want to get a radeon 7870 with the boost, which ive seen on ebay around $190. I would prefer to find combos to save money, primarily on the cpu and mobo. I would really like to have a motherboard that could support crossfire for the 7870 down the road. And also a sufficient power supply.I would like 8gb of ram, but please no fancy cases. I would prefer a quad core to save money if cheaper. Any chance any of you have a computer build suggestion i could purchase around $600-$650 that meet that criteria? If not for the 7870, please give me other good reccomenndations. Ps: only including one 7870 in the budget