Power supply for this rig??

hello peeps...im wondering what type of power supply would a rig like this need..im not sure how many WATTS it should be..if you can help me out would be great. thanks in advance.

Intel core 2 duo 2.13 ghz

Seagate hard drive 320g

OCZ Dual Channel XTC 2048MB PC5400 DDR2 667MHz  (2 x 1024MB)

Geforce 8800 GTS 640mb pci express

ASUS p5nsli mainboard

DVD drive and DVD writer Drive

hello peeps...im wondering what type of power supply would a rig like this need..im not sure how many WATTS it should be..if you can help me out would be great. thanks in advance.

Intel core 2 duo 2.13 ghz

Seagate hard drive 320g

OCZ Dual Channel XTC 2048MB PC5400 DDR2 667MHz (2 x 1024MB)

Geforce 8800 GTS 640mb pci express

ASUS p5nsli mainboard

DVD drive and DVD writer Drive

ytrewq1029

This is just perfect for that setup.

Corsair 620w

awesome thanks for the help guys..aslo can someone explain me what this means..i was lurking the GPU system requirements and i found this:

450W PCI Express-compliant system power supply with a combined 12V current rating of 30A or more.

not sure what that means :( how do i check if a power supply meets that?

lso i was more into this:

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1273350&CatId=1079

is that brand good enough? how are the specs looking!!