New PSU?

I currently have a 250W psu in my Dell Dimension 8250, here are the specs:

p4 2.66gz
256mbs rdram
dell mobo i850E chipset
80GB hardrive 7200rpm
Geforce 4 MX420
Creative SB Live! Series
DVD CD floppy Drives

Im wanting to upgrade to 756mbs ram and swap my gpu 4 a geforce 6200 or 6600, will my psu be able to keep up? I saw a review with a system similiar to mine with a 6200 and it used about 210 watts at peak gaming ussage but I was thinking mayb it would b safer to have more than 40w to spare. Also the Geforce 6 series needed 12v supply, thats nothing to do with the AGP slot, its all provided by a direct connector to the psu rite?