Passmark is unreliable. Since the PSU can run a 9800 GT it would obviously be able to run a 7770 too, since it draws less power. The 7770 does draw more power than the GTX 650, but it's about equally efficient with that power - giving more performance. It's a better deal.
Although you don't list a budget, I would go the video card route and get a 7770. The rest of the system is usable though. You may want to consider overclocking that cpu to at least 3.5GHZ and throw on a Coolermaster 212 EVO heatsink. That will give a cheap boost to performance.