building a computer

I'm more or less new to computers and own a dell atm. =(
Here is the parts list that I made earlier:
2x 17inch monitors, http://www.newegg.com/Product/Product.asp?Item=N82E16824009036
case: http://www.newegg.com/Product/Product.asp?Item=N82E16811156177
extra fan: http://www.newegg.com/Product/Product.asp?Item=N82E16835129243
motherboard: http://www.newegg.com/Product/Product.asp?Item=N82E16813131540
memory: http://www.newegg.com/Product/Product.asp?Item=N82E16820145587
2x sli 7800gt http://www.newegg.com/Product/Product.asp?Item=N82E16814121004
cpu http://www.newegg.com/Product/Product.asp?Item=N82E16819103603
soundcard: http://www.newegg.com/Product/Product.asp?Item=N82E16829102003

The prices add up to about 1500 with the two monitors, I have speakers, keyboard, and a mouse.

Including things like wires and such, what all do I need to consider/know about/buy along with all this. Or maybe any suggestions to replace some of these parts with similar priced products that might perform better with that set up?

Any help appreciated.

>>1
Okay, those graphics card you link to are not 7800GT, but 7600GT. Why? Why in the hell would you buy 2 of those, and put them in SLI? For the same money you can get a single 7900GT or 7900GTX, if you score a bargain, and still get practically the same performance with only 1 card.

And try to upgrade from 2 7600s using SLI when you desire more power, oh wait - you can't because you got both your slots filled with some weak budget cards! That's like SLIing 2 6600GTs, sure it's possible, but why?