Personally, I LOVE BitMinter and will be going back there when I have a BTC-appropriate mining setup.

As for your hashing speed, it looks like most users with your card get the best results using Phoenix.

Try Phoenix svn with phatk kernel and try these settings: fan 100%, vcore 1.1750 V, 72C, VECTORS BFI_INT AGGRESSION=15 FASTLOOP=false -k phatk

You should see upwards of 400 MH/s with that setup.