Video/Mobo card trouble

Soooo, call me a moron.

I currently have a Intel DP45SG board, running a ASUS Radeon EAH4670 for a video card.

Have a Core 2Duo E8400 3 GHZ

This thing has been nothing but trouble. a month and a half ago, I had an issue with the Video card being badly designed for the mobo, being a tad old ( I got it on a provisionary basis, was gonna upgrade as soon as I got more money), causeing an eneltrical short in my system and shorting it every 5 minutes, crashing my computer (seriously I was losing it)

So I say sure, I was gonna upgrade my Video card anyway.

Of course I kinda suck when it comes to hardware compatibility, so I didn<t check my stuff before going out and ordering 2 Geforce 260s, thinking :"Hey, I'll put them in SLI!"

So now i'm stuck with an ok Mobo, but 2 video cards that can't work in SLI cause the board won't support it, and that I can't set up in Crossfire cause the cards won,t support it.

So here comes the decision. Should I just use 1 video card, e-bay the other one, and cut my losses?

Can I even TRY to replace my Mobo? I've looked around and I'm seeing a lot of comparisons with the 750i out there, but then again, that won't take my DDR3 ram. I don,t want to blow a fortune rebuying my whole PC here, I just bought this system 8 months ago. That and I'm not sure if I'd feel comfortable fiddling with trying to get a new board but together. (Never fiddled with one)

Otherwise, will my board still use both video cards say if I don,t put them in SLI?

Any advice here is VERY welcome.