need help picking a power supply

hey, i need help picking a power supply for my computer. i was going to get this. http://www.newegg.com/Product/Product.aspx?Item=N82E16817151095

but it's out of stock right now and i'm ordering the rig tomorrow. will any power supply fit my computer? i was thinking of getting this one since i can't get the other one. http://www.newegg.com/Product/Product.aspx?Item=N82E16817139020

how do i know if it will fit the rig or not? thanks

also, is 700 watt enough to power most computers? what about 620 watt?

 

Yes it'll fit & work, yes it should power your rig fine(unles you're running like CFX/SLI 680s/7970s etc)

 

Get this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16817139020

Unless you're going for a super gaming computer, that PSU will do you perfectly fine. Corsair are a very good quality brand also.

 

I would recommend this one:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151106
They are 24/7 in our servers for a year.

 

I second Laptop. As far as PSU's go, Corsair is one of the top dogs.