Can I mine with BFGMiner on an ATI Radeon
You need to use cgminer-3.7.2 or earlier.  For some reason, GPU mining was removed from subsequent versions.

Cgminer is the best available miner for your purposes.  Con Kolivas is one of the world's great programmers, and we are lucky to be able to use his software.

Please also be sure to read the file SCRYPT-README to get reasonable performance.