Out of all the stuff you've got atm, I'd say the gfx card is your biggest bottleneck. However, with the new cards scheduled to be released pretty soon, I'd suggest waiting a little before buying anything. See which prices drop, how much the new ones cost, how well they perform, etc.
Apart from that, maybe buy a new HSF for your cpu and OC it. That's still a pretty decent cpu, and with an oc on it I'd think it should be fine.