i have a 8350, 8 gigs of ram, and 650W powersupply. And to outlander no its factory overclocked
OK - assuming the 650w PSU is of decent quality, you have more than enough juice for
a 7970 if you choose to go that route.
If you are located in the US, maybe you could save for another month or so &
get a new 7970 as it's only $50 higher than the used.