I really hate to post this, since there's so many others.  I've tried several PSU wattage calculators to find they all give me different answers.
 
Case: Antec 900
Proc: Q9450
GPU: 9800 GTX (just 1)
Mobo: Gigabyte-EP35C-DS3R
HDD1: 74gb Raptor
HDD2: 7200 320 gb barracuda
OD: DVDR/combo drive
2-4 sticks of 2gb ram as well (havent decided if i want 4 or 8 yet).
 
I'll replace the stock fan on the processor since I'm slightly overclocking.
 
I wanted to get the PC Power & Cooling 610 Silencer (trying to build a *very* quiet system)
Want to know if I need to bump it up to the 750W PCP&C one... (40 dollars more =\)
 
I'll probably charge my iPod and have about 2-3 other USB ports filled on this thing too, so that should factor in I suppose.
 
This computer isn't built yet... Getting parts as fast as I can, as fast as my bank account allows me to
 
 
Thank you all for reading this, and for your knowledge imparted onto me

The PP&C 610 should be able to handle the 9800GTX.

Heck, a Corsair 500W could pull it off.

I have the Q9450, 2x 8800 GTX, 3 HD's , internal watercooling, 2x DVDRW's, and 4x 120 fans.
 
My Thermaltake toughpower 500 runs everything except the second GTX, and the digital display it has is in the 360-390 watts range at load in Crysis. Similar in 3dmark06, but around 340 in prime 95 with all four cores smoking.
 
The second GTX is on a Thermaltake power express 250 psu in one of my bay slots.
 
The GTXs are running over Ultra speeds and the Q is at 3.4.
 
So the 610 has a 30-40 percent headroom to stretch.....  
 
Get it and worry about something else.

like how im going to afford that system?