To start with, I think you're looking at the situation from the wrong direction. That said, look for a psu that has 18-20 amps per rail, and also one from a high quality company. If you get a 8800 GTX, you probaly should look for a psu that's rated around 600wt to 700wt, depending on the total amount of hardware that you have. Don't bother looking for anything under a 500wt output.
A convenient way of figuring out the size of a psu that you need is to use a psu calculator, such as the one at www.extreme.outervision.com/psucalculator.jsp. In the forumz, there is a sticky in the hardware group under power supplies called PSU 101. Read this for better understanding. It also has a link to the psu calculator, just in case the one I typed doesn't work right. It also has a PSU List that tells both recommended companies and companies to avoid.
Yeah, I believe the 8800 GTS recommends 28A on 12V, includin other components I believe. I suppose any of those that you listed would work, but I'm with bruce and sailer too. You should get a good PSU. Something from someone a little more reputable, like Antec, Thermaltake, etc. I heard OCZ makes some pretty good ones too. This would definitely fit the bill: http://www.newegg.com/Product/Product.asp?Item=N82E1681... Not a bad price with the rebate too.
Thanks guys I know what to look for now, haven't made up my mind yet on the PSU but looks like I'll be spending over 100 instead of 50 lol. The Antec TP3-650 looked nice but it looks like they're not making them as good as they used to, so I'm leaning towards a CORSAIR CMPSU-520HX for the 5 year warranty. It sucks you can't just add up the amps on the rails, thanks for the correction.
The FSP power supply actually has 35.4 amps... confusing label Does FSP use the same MFG as OCZ on this PSU?
The GTS wasn't considered at the time because I was thinking I either get the best or don't spend a whole lot and upgrade later. I may end up with that though due to an increase in the expected PSU price. I have to get a video card right now though since my 6800 is AGP.
I already have the hard drives, the Raptor is for gaming and the 250 GB is for everything else.
The graphic requirements are pretty high on Vanguard if you want high quality. Consider it similar to Oblivion. That's why I chose a GPU that much better than the CPU.