"Matt" wrote in message
...
I am assuming that you can only run 2 cards SLI with PCI Express...
correct?

Yes, and only on a motherboard with the nVidia nForce4 chipset (though
that'll change with a newly-announced Intel chipset).

I'm building a computer for a friend of a friend that has already has a
6800GT AGP card. He's not going to like having to get a new video card if
that's the case...

Simple. Sell the 6800GT on eBay. It will actually fetch a decent price
compared to the cost of a new one today.

Also would an Antec TruePower 2.0 TP-II 430 480W Power Supply be enough to
power the system with 2 6800GT's (providing he can get two new cards), 1
WD 74gig Raptor, Asus A8nSLI Deluxe, & a DVD-Rom drive? Or shoud I step up
to a 480 (or possibly higher).

The 430 should be able to handle it. Antec PSUs are solid. Keep it unless
you see problems like repeated crashing at boot or during a game.

--
"War is the continuation of politics by other means.
It can therefore be said that politics is war without
bloodshed while war is politics with bloodshed."