You might want to try a Radeon 5670 maybe?
That's designed for a 400w psu, i think you could get away with it.
Been a while since my post but thanks for your advice. The 5670's working great with my 380w PSU, no issues whatsoever. Very quick card I'm happy and all for $89.00. Just unlocked one more core with my phenom II X2 555 and no issues with the PSU. Tri-Core for $52.00!! Thanks again!