9800GT SLI vs GTX 275 plus dell support rant

I got a XPS 730 system from christmas and it came with 2 9800GT's. all well and good accept one was Dead and would lock up my computer, after some trouble shooting i found it was the second (slave) gpu and contacted dell support, after hours of explaining the problem they decided that the best course of action would be to replace the motherboard . I knew this would do nothing but i had no choice. later the technican replaced the mother board and guess what didn't do a thing. So this time they agreed change the gpu and life was good intill last week when the second gpu died again and after contacting dell. They said that the motherboard needed to be replaced. At that point i said forget it. i decided that if i want it done right i would do it my self. I am planing on buying a GTX275 and eliminating the SLI because i had issues with that too. i ve got a friend lined up to buy the good 9800 from me. Thats the story, kinda long

My specific questions are
Will the 275GTX give the same or better performance (im not expecting better, just for it to work)?
Has anyone else had same problems with dell or is it just me?
Also is SLI unreliable for everyone or am i just very unluck?

PS. dont spam me with "you should build your own" it was a gift from my parents and nice system

A single GTX275 is a major upgrade from 1 9800GT, and a downgrade from 2x9800GT.

Do you still have your warranty? If so, you can just get another 9800GT.

If not, then sell the 9800 and get the 275 as customisbetter mentioned.

Thanks for the replys I want a head with my desicion and pick up a gigabyte GTX275, im very happying with it, haven't had a single issue with it and i have gotten a 5% - 10% performance boost before overclocking, that game me another 10%.