Upgrade HP a6000n or New Build???

[Necorum]

Socket AM2 i believe on the motherboard (i own a gigabyte am2 nforce430/6150 chipset board)
http://reviews.cnet.com/desktops/hp-pavilion-a6000n-athlon/4507-3118_7-32384248.html?tag=mncolBtm;rnav

ATI 4670 400W Power Supply recommended. $66
http://www.ewiz.com/detail.php?p=AT-4670HDM&c=pw
OR
9600gso 768mb 55 bucks
http://3btech.net/pnygepny9676.html
PSU's
Coolmaster 650watt +12V1 @ 16A; +12V2 @ 16A $54
http://www.ewiz.com/detail.php?p=PS-NW-650B&c=pw
OR
Cooler Master eXtreme Power Plus Series 500W $39
http://www.amazon.com/Cooler-Master-eXtreme-ATX12V-Active/dp/B001G0WPLK%3FSubscriptionId%3D16330PR1NAHTNCZP5602%26tag%3Dpriwat-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB001G0WPLK

If this machine is for dolphin then this selection might be better

AMD Athlon II X2 240 barebone kit $109
http://www.smksuperstore.com/product/54AMXII240-51410.aspx?r=p

or add this to current setup
amd x2 6000 $54.99
http://www.ewiz.com/detail.php?p=A64-6000CZ&c=pw
and
GeForce 9600GT 512MB 65.99
http://3btech.net/pnyge9651pci.html
or
Radeon HD4670 512MB 66.99
http://www.ewiz.com/detail.php?p=AT-4670HDM&c=pw