So wait, you're going to power a rig from the stage loud enough at the Echo or the Troubador to overcome your guitarist without going direct to FOH?
Personally, I wouldn't do it. I think you'll get lost in the mix, or become so boomy that you'll lose all definition.
Nonetheless, in any event: I'd go with Bergantino CN series. You could do the CN 212 for under 50 pounds and blow away the guitarist. I use a single CN 112 on small stages, obviously going direct from FOH. Beauty of that rig is: 28 pound cabinet, 4 pound GB Shuttle 6.2, and a bass case. One trip. Donezo.