Will this PSU be sufficient?

Okey duud Im geting a new Graphic card for my PC was wondering whether 450 W psu will be enught coz the crap ass 9500gt did well :P

My Rig - Core 2 Duo 2.8 Ghz

Foxconn G31MXP

4 gb DDR2 Ram

and this is the Graphic card im hoping to get HD 4850 1gb or an 8800 gts 1g

I also have a creative AUDIGY 2 soundcard.

Will that PSU be enough or which PSU should i get?

Which of these 2 motherboards are better?

http://www.intel.com/Products/Desktop/Mo…

or

http://www.oneshop.co.za/p~foxconn-g31mxp-mb-chipset-motherboard.html

the 1s link wont work try this

http://www.intel.com/Products/Desktop/Motherboards/DG31PR/DG31PR-overview.htm

so the FOXCONN 1s better? even on performance?