Dell :: Replacing GPU In M1730

I am down to 1 GPU on my M1730, in the interest of replacing it , from the forum sticky these seem to be the options

XPS M1730
Nvidia 8700M (both single and SLI****)
Nviida 8800M GTX SLI
Nvidia 9800M GT SLI
Nvidia 9800M GTX SLI

(I assumme this list is complete still . i.e. no 260's or 280's available)

Other than Dell or EBay are there any other sites , suppliers that people know of who might supply one of the above

DELL want 340 + Vat for a sli 8700m and there is every so often a 8800M for sale on ebay but they typically want approx 500 pounds for it (anyone had experience of buying one?)

I am dubious about the 8800 as evidence suggests it runs hot so would prefer a cheap 8700m or a warrentied 9800M