The one thing that you MUST accept is that if you're going to be playing with more than one acoustic guitar and want to be heard, you're going to have to plug in.
Beyond that, the best advice I can give you is to find one that fits you and is comfortable to play.
I've played many...and while the TC / Taylor / reasonator bass are the loudest of the bunch, they are still not loud enough to be effective without plugging in.
My best advice is to find a bass that fits and has the vibe and action that you like, and plug it in. A surprisingly good find for me was an older Fender BG-29.