Question on Nvidia cards

Just saw a deal on Frys for the BFG GeForce 9800 GTX Video Card (PCI-Express, 512MB). Its 150 after rebates.

http://forums.slickdeals.net/showthread.php?sduid=93352&t=872174

I was thinking about getting this card but would it be more beneficial to do SLI with two of these 9800's or buy my one below.

ASUS ENGTX260/HTDP/896M GeForce GTX 260 896MB 448-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail
(http://www.newegg.com/Product/Product.aspx?Item=N82E16814121257)

well actually i just read up that i can't do SLI on a x38 board unless its a crossfire video card. That's true right? Then if this is the case, i was thinking of these as a double but then i'm not sure if these two are better than the gtx260.

GIGABYTE GV-R485-512H-B Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125224

Two 4850s is about as good as a 9800GX2, if that answers your question.
Also, get the cheapest brand possible unless you have some strange affinity towards Gigabyte Technology.

I'd say just get a single 4850 (cheapest one you can get or something like $150 AR). Take the extra cash and get a new CPU. With a fast computer and a 4850 you can run pretty much every game at max settings unless you have some insane resolution for a 24"+ monitor. Once it comes to the point where you will need more speed you can always get another 4850 or sell yours and buy the next fastest card for only a little more.

If you are already planning all that and are intent on x-fire, well the 4850 will do crossfire is what i've read.

Yeah... That damned Opteron won't be your friend...

Oh my fault i didnt mention i am upgrading to a Intel Core 2 Quad Q9300 Yorkfield 2.5GHz 6MB L2 Cache LGA 775 95W Quad-Core Processor - Retail and also an Asus x38 board. Hmm, i'm pretty set on my new machine but i'm torn between graphics cards. I originally was going to get the ASUS ENGTX260/HTDP/896M GeForce GTX 260 896MB 448-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail but then i saw the Frys sale for 150 at that 9800GTX. But i now know i can't do SLI on that x38 board so one 9800GTX won't compete with these others so my options are 2 4850 cross fires or that GTX260 card above.