The best overclocking tool for the Radeon's, IMO, is the rage3d tweak available at
http://www.rage3d.com/r3dtweak/. I have a AIW 7500 ATi Retail and its stock is 258.8/360.0 clock/mem. Its a fine system, but it doesn't hold a candle to my everyday system with the 8500 128 or my power system with the 9700 pro. I'd start with a 10mhz o/c and run 3dmark, then just stepping it up little by little. Its can be a long process, so be patient. By little by little, I mean 1 mhz at a time. If you are brave and have money, try for 300/375 and adjust for artifact removal. Make sure you have tons of air flow and a clean board. Blow it out with compressed air (while off). Good luck.
