Im pretty much decided on getting a 780i mobo with 4 gig of ocz sli pc2 6400 and a core2 E8400.
As you can see this isnt the latest technology as Im on a budget.
Im unsure about which Graphics card/s to get.
Im planning on building in a couple of months so prices/budget could change a bit, but at the minute I can only afford one card.
My options are get an xfx OC 8800gt then get another when I get the pennies ( currently £140 each )
get a 9800gtx and then get 2 more when I get the money( currently around £200 each )
Im thinking the first option will be most cost effective as when the 8800gt sli starts to struggle in games the next gen cards will be out. Also doesnt the performance gain per card in sli drop rapidly?
9800GTX > 8800GT, but for price per performance wise 8800GT is the best. Depending on your budget. I suggest single 8800GTS 512Mb, but the decision is yours to make.
For SLI thing, unless you SLI now, there no point to 'upgrade' second one when your first card start to struggle as at that time the newer and more performance card is already available and cheaper and probably will outperformed your present SLI configuration.
TRI sli 9800gtx is a total waste of money. To begin with the 9800gtx @ factory clocks is very underwhelming, buying a second gives you about 50-70% more performance for twice the cost. Getting a third bumps that up to only about 50-80% more performance than a single card for 3x the cost.
The most sensible thing to do would be to buy an 8800gt and then either step up or trade up to the new generation of cards. If money is not a concern and you want the system now then go with either the 9800gx2 or 2 sli 9800gtx. Tri or quad sli is just not worth it at the moment.
8800GT, GTS and 9800 GTX are using the same G92 chipset, only different in core/memory/shader clock. The differences between three of them is not very much. IMHO and from what I personally suggested you earlier was 8800GTS because the stock cooler of 8800GTS is DS and you'll never have a heat issues compare to 8800GT stock cooler which is SS. If you happen to buy 8800GT stock cooler and replace the stock cooler with aftermarket cooler, the total price is almost similar to a 8800GTS while you'll get an extra performance over it.