drop down to a X2 3800+ as the only difference is the speed between the 4200+
i say get rid of the abit board and either go with a DFI nF4 SLI-DR or nF4 ultra-D lanparty series
you dont need to buy IDe cables, sata cables, etc they all come with your mobo.
i wouldnt go with corsair XMS ram cause they are overpriced and just plain bad
If you are OCing go with the OCZ platinum series, or not then go with some corsair valueselect as valueselect=expensive ram and expensive ram > valueselect only when you are OCing.
maybe go with a seagate hdd as they last longer, though the samsung is supposely quieter