i had the fishman ellipse matrix blend installed into my Martin D-15, because my band will be playing shows soon. i'm not getting a decent sound out of my Mesa trem-o-verb (w/ 4x12) like i was hoping. the Ultrasound amp I played at the store was 100% better. i dont know much of anything about acoustic amps, i was hoping to get some help picking one out, or i'm open to other suggestions for getting a good live sound. brands i've been lookin at online have been, Roland, Ultrasound, Fender, Marshall. i'm not looking to spend a lot, just enough to get me by for live use. the band includes, drums, keyboards, electric guitars, electric bass. what type of wattage would i need for smaller shows, assuming there wasn't PA system micing available? also what about tonal characteristics of these brands? i plan on trying them out at the store also.