I Love the Digitech unit here it is in action in my basement (RP355): http://www.youtube.com/watch?v=ZV2Ut2f4ZNk
Best, Rob Paparozzi
Digitech RP255 or RP355, Line 9 M9 or M13, and the Zoom G3 or G5 are all great units. If I use compression, I generally use a dedicated pedal, and I find distortion pedals to be hard to tame live, but all of those unit will give you all of those things in spades.
H