I am replacing my power supply, motherboard, RAM, processor, and video card (and DVD drive if i can, because I want to keep my PATA hard drive and my current DVD burner is also PATA - most motherboards now only have one PATA connector)

I'm on a semi-tight budget right now, so I'm going for expandability. Later this year I'd love to jump to a Q9450 (I do a lot of video editing and 3d rendering in addition to gaming) and a 9800GT or even GTX.

Intel E2160 processor $70
Gigabyte GA-P35-DS3L motherboard $90
G.Skill 2GB (2 x 1GB) PC6400 memory $45
Sapphire Radeon 3650 GDDR2 version $80
OCZ GameXStream 700W power supply $135

My budget is about 450 dollars after tax and shipping.

I have some specific questions:
Should I spend the extra $20 on the video card and get the GDDR3 version? Right now the most taxing game I own is probably Half Life 2 Episode 2. I plan to get a new video card before this fall.

Should I get the single 2GB stick of RAM for the same price?

Should I save $30 on the PSU and get the 600W version instead? (Or even a completely different model?) I may go SLI after my 9800GT or whatever becomes insufficient down the road, although at that point Nehalem will probably be out and I might be looking at a total system rebuild again anyway. (Or is it a sure thing that PCI-Express will still be the standard graphics slot even after Nehalem?)
Obviously 700W is total overkill for a 2160 and a 3650, but what about a q9450 and a 9800GT (or two?) Should I be instead looking in the 500-600W range?

Any other thoughts? Thanks for your time.

Your build looks okay for a budget build in my opinion.

You should save the $20 regarding the video card since you're planning to upgrade when the 9800 series hits.

Dual channel over single channel.

I'd say stick with 700W PSU if you're planning to go SLI. That P35 chipset will have to go which means new motherboard if you're going SLI. Or go crossfire (since you alread have one ati card) and the new motherboard won't be necessary.

Tough call really. Since you're into video editing and rendering, I would plan to upgrade to a quad core build.

would the 700W be enough to power dual 9800GTXs (assuming they have the same power requirements as the 8800's?)

If I were planning on just getting a 9800GTX (or 4870?), how would my PSU requirement change? I could probably do with the 600W model, couldn't I?

Don't look so much at wattage, I think most guys here agree that your main thing is the amps on the 12v+ rails. The more the merrier.

That is true.

I want to be able to run a q9450 and an 8800/9800gtx. Are there any power supplies that stand out on price vs quality that could run that? Does Mushkin make good power supplies? How about this one? http://www.newegg.com/Product/Prod [...] 6817812004
Four 20amp 12V rails, plus it's modular and only 100 bucks. Is this too good to be true?

You can get a good deal on the Corsair 620 here;
http://www.buy.com/prod/corsair-62 [...] 70718.html
2 gig of BALLISTIX FOR $32;
http://www.newegg.com/Product/Prod [...] 6820146565
E2180 for $50;
http://www.tigerdirect.com/applica [...] No=3505668

I think the OCZ would handle a 9800 card just fine.

As for other power supplies, I am partial to Corsair and Seasonic brands as those are the only two I have ever owned and have never been dissapointed.