Acoustic brand amps? Or just an acoustic guitar amp?
My wife has a little green Marshall AS50. It's good for small gigs but I've found it a little underpowered if you are running vocals into it as well. I would definitely be looking in the 200 SS watt range if I was shopping, but it's gonna depend on your power needs. The Marshall has been decent for her but I don't have a lot of faith in it's long term build quality. Pretty much the case with a lot of new cheaply made gear. It's better than the Fender accoustasonic, that thing was a pile of junk.