Definetly go Socket AM2 man.
i mean its practically the same price and its more future proof.
It looks like you are planning on doing SLI down the road with that lower end 7300GT
i would get atleast a 500 Watt powersupply
I use this power supply and i very impressed with it
this one is only $45 and looks good as well
Personally i would junk the 7300GT and go with this
$113 after rebate http://www.newegg.com/Product/Produc...82E16814143049
(that would be pretty nice in SLI)
If you cant afford the higher end vid card at least go for a better powersupply if you plan on SLI down the road.
and if you do go with the video card you DEFINETLY should get one of those PSUs.