-The processor is fine but you could get a 3200+ or a 3000+(get a Venice core), for gaming what matters most is the graphics card not the CPU.
-Motherboard: You shouldn't spend your money on SLI.
If your graphics card is not at least a 6600GT you can't even do SLI.
-Graphics card If you get a slower CPU you can put the money you saved from the CPU into buying a better video card.
-Get a kit of RAM (2 X 512) from a known vendor.
-Sound Card If you don't have a good set of speakers you don't need a sound card. Get a good set of speakers with the sound card money and use the onboard audio while you save some more.
-DVD I would get the NEC 3540 ($40). It's a great drive and it doesn't show on the price.
I don't know where are you buying but newegg.com has good prices.
<font color=red>It's impossible to make anything foolproof because fools are so ingenious<font color=red>