the psu is too small for a q6600: (antec might work but it could fail - i have a 125w p4 system with 8800gtx and raid its on neo 550 so they are really good) silverstone are the best - they blow cold air out the rear most of the time so they are super effecient
silverstone strider 750 $137 at east luna or at least the 550 neo he - when you crank your q6600 up 3ghz+ you need 150w
- use a thermalright ultra-120 cooler with 120mm fan on fan control i get 2500 rpm lighed one -- you can get them from koolance hard fince 12cm 2500rpm with lights!
hdd: raid o with intel is flawless i have been running raid10/0 that is i have half of 4x160gb drives in raid 1o with xp and half with rc-1 vista
you might even put your os on raptor then run raid for storage - i build alot of 3 drive systems 1 os raptor and 2 sata or ide in raid 1 0r 0
ram - it u use 2gigs u can use a $40 4gb usb for superfetch it works well for low ram systems - 2 gigs works great 4 gigs is kinda of overkill
The DS3 and most current mobos have 4 slots that can use 2gb sticks
If you are going to clock the e4300 to ~3ghz, you will need an aftermarker cooler.
You have the right plan, you need RAM, HD space and CPU power.
1) Q6600 is a 1066 FSB part, unless you mean the yorkfield due out in Q4
2) I wouldn't buy a board that depends on a revision number, I just don't like the idea of "chance"
3) From what I can see all 965 boards (680i/RD600/650i also) support 8GB of RAM
4) wait for a X2900XT if you can, based on benchmarks I saw today it will hand the 8800GTS its ass on a silver platter and AMD intends to match the GTS's street price.
5) For OC'ing a quadcore I would really suggest paying out an additional $50 or so for a good air cooler. It won't add much to the cost of the system but it will make a world of difference with temps (and overclocking if you go that route)
For an actual board recommendation I would need your price range. The DS3 is about 120, but is that all you want to spend, or is that a minimum?