BTW XFX 9800GTX+ PVT98WYDFH is only 179.99 at Newegg.ca. After rebate thats $154.99.
Newegg.ca - XFX PVT98WYDFH GeForce 9800 GTX+ 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards
I've never folded with either but the charts say 2 9600gso's would outperform the single 9800gtx+ by about 30%.
I once considered grabbing a couple 9600gso's as I read they were the best bang for the buck for ppd. but that was back in October and they were selling them for $36 down in the states. heres the article regarding them and folding.
Legit Reviews - F@H - 4,500+ Points a Day w/ a $36 GeForce 9600 GSO - What $36 Buys You When It Comes to Folding
Also if you have a little more money might I suggest.
NCIX.com - Buy EVGA E-GEFORCE GTX 260 Core 216 576MHZ 896MB 1.99GHZ GDDR3 PCI-E Dual DVI-I HDCP HDTV Out Video Card - 896-P3-1265-AR In Canada.
But I'm biased when it comes to 260s