Old computer looking for upgrade

[Aphael]

I recently am interested in upgrading my old computer.
It has a 8500gt,athlon x2 250, antec basiq power 430, and a GIGABYTE GA-MA790X-UD4P.
I would like to upgrade the gpu first like a hd 7790 or gtx 650 ti boost.
Will these graphic cards run with enough juice because of the limiting factor of 430watts?

 

[Aphael]

I was thinking of the phenom ii x4 840 or 965 along with a new motherboard that supports ddr3 memory. Would the same power supply be able to support the new cpu since they have higher power usages?