I use a little Phil Jones combo (BG-75) with a FIshman Platinum Stage preamp for acoustic get togethers, I'd probably just scale that up for louder scenarios and use my Platinum Pro for its stage friendly features. A BG-450 would probably do you, what sort of volume do you need?
Alternatively a mini head with a decent small cab, a lot of heads aren't voiced particularly well for acoustic music though. A suitable preamp like the Fishman into a compact powered PA cab might be preferable.