Addis is right but in many ways SLI can be somewhat economic. It's a pricey mobo but you could buy one good video card to start, and when you get the cash you can buy the exact same card, except it's cheaper now and you've just given yourself a major performance boost for less. The big problem is depending on when you buy the second card new, easily faster cards with all new features may be out and you'll but using yesterdays technology but it's a case by case thing I guess. Great setup though MrChris!
Anyway here's what I need besides what I've got (see "my computer", ProcalX will already have seen this):
1 gig of Dual Channel PC3200 GSkill memory
some soundcard using VIA Envy (still not entirly sure yet)
Samsung SyncMaster 19'' CRT
Logitech 5.1 speakers (although 2.1 will fit a whole lot better)

In the rather distant future I want a 'card with at least 256MB's of memory and what ever AMD comes up with in my low pricerange in about 6-10 months.