I have a Cube 30 and love it. Any of the Cubes should be great. You can run it to a PA for volume if you have to I suppose. I've run mine into my Bose PAS.
2 ...electrics
1 ...4 string bass
6 ...acoustics
1 ...Yamaha Silent Guitar
1 ...Line 6 Acoustic Variaxe
= 11.
That's all I think, after all I'm just a keyboard player, who grew up playing sax.