ehh, I know some people like gigabyte but personally if I were to suggest 3 manufacturers to you I'd go in this order:
that isn't to say gigabyte is bad, I just think theres better out there especially when it comes to OC'ing.
You could just get the nf4 Ultra-D board...it's not QUITE SLI, but it can utilize two video cards...it wouldn't be AS fast as SLI though but hell it'd still be powerful and save you money since it's not as expensive as a SLI board.
Theres also this:
that'll show you how to mod the chipset so that it WILL basically be a SLI board, however I remember reading at some point DFI was going to start making a new revision of that board to disallow you from doing such things....not sure if they actually did that or not so you'd have to read up on that.
What I don't want to happen is that I make the jump to PCI-E now and then a year later or so, something new and better than PCI-E comes out
Doubt it dude...look how long AGP has been around, PCI-E isn't even that old yet, nor have they come even close to utilizing the bandwidth it can endure...currently the cards in terms of bandwidth through the interface are no better than AGP 8x speeds, but they'll surely improve in the future.
Regardless to 6800GT's especially if OC'd to Ultra will last you 2-3 years easily unless games just make huge leaps