[OHTEHNOES]

So, my computer just can't be fixed, I have a Sapphire 9600 XT graphics card that crashes it every 17 minutes, and despite all the fixes suggested here:
http://geek.pandemon...600-pro-solved/

I haven't been able to fix it.

Here are its specs:
AMD Athlon 64 3000+
ECS 755-a Mobo
Memorex 8x dvd drive (r/w/rw)
32 Gig hd
Creative Live VALUE soundcard.
Sapphire Tech ATI 9600 XT (THIS CARD IS THE DEVIL )

So. I'm building a new computer, and want a little advice.

I think I'm going for these specs:

Case with 450-550 power supply. Hopefully something pretty too. Any advice?
OCed AMD x2 64 3800+
Asus motherboard? Not sure.
BFG 7800GT or whatever nvidia SLI card I can get around christmas time for around $300?
New HD, probably 150 gigs, maybe 250 if there is a nice enough sale.
Creative Audio, anything in the $80 range


Ok, so I guess my biggest question is, Does SLI really matter? I mean, would I be able to upgrade in two years (as in, my specs move down but then I get card and they go back up to top) by buying another identical card? Would that give the gains I would need to keep cutting edge? Or is SLI not really that great?

I checked other sites and couldn't find an answer to how advantageous SLI is.

yours truly,
OHTEHNOES