Two 6600s wouldn't be a bad idea. Have you checked on the monetary efficiency of buying a single high-end part? Not that I have; I'm just suggesting looking at a few benchmarks of SLI 6600s and comparing them to that of a single 6800. Plus it gives you the option to go dual-6800s later if you REALLY wanted to crank the speed.
ditch the 3500, get a 3000 venice for 100 less and overclock it to at least 3300. if it won't overclock, oh well, 500 mhz is negligible.
You really need to think about the sli thing. is buying 2 cards worth it, really? sli is finicky, game dependent on improvement, and requires nvidia to produce new drivers for each new or old game supported (crossfire has its disadvantages too). 6800 gt might be a better way to go until next years upgrade. Or do the gigabyte 2 gpu on one card deal.
there is an antec true power 420? that should cover you. very robust.
I don't do cases. theyre just tin boxes to hold the good stuff.
why not water cooling? i have not seen anyone in here take the plunge yet (pun intentional).
why only 36 gig on the hd? and are you sure you want a 10,000 rpm vacuum cleaner/bomb in your system?
i was thinking about the 6800, would ultra be worth it? What is this about the Venice core chip that would make it better? and i choose the 36 gigs because the 76gigs would make it 150 more... I have 600 plus space on the file server and this comp will allways be around it.
I'd say the OCZ Powerstream 420W PSU or greater. I love mine. It's very nice, has the 24 pins, as well as it has dual video card or HD molex lines. And the powerstreams have enough amps on the 12v to make it nice overall.
Oh and Venice definitely.
And I'm sure you could find an OEM 74.6GB Raptor for less than $241
For case, go for anything with 120mm fans. Having at least one for intake and another for exhaust is a must for hot components, and can really help to elevate those noise issues. Style-wise, there's a large number of varities you can choose.
Antec are a very good company to go for, and Coolermaster produce a very cheap case with 120mm fans (or go for the Stacker, but that's pretty big!). I think some people consider the design to be pretty important aspect of the rig, so just choose one you like the look of. Also, a roomy case might help when building the comp from the ground-up.
I have a simple Antec on the other comp, it hasn't failed me yet. If you want a different choice, there's always the Tagan, but it has quite a lot of cables you might not need