If you are spending that much on the mobo, proc and vid cards, why are you scimping on the ram? I would suggest you start off buying just 1 7800GTX and spending the extra money on the fastest ram you can find. You can always buy your second 7800GTX later and do your SLI thing. After all, with the ram you linked to, that would definitely be the weakest link in your setup and buying some ram that can run 2-2-2-5 timings at 200 HTT or tight timings at higher HTT speeds if you plan to overclock would be your best course.