hello,
I have the perfect answer for you try the Mark Acoustic ac 101
10″ speaker + 1″ tweeter, 2 channel, effect ( reverb, hall, room), line out, small size only 10kq, 150w or 200 if you add a 4ohm box.
more info here :
http://www.markbass.it/products.php?lingua=en&cat=2&vedi=130
This best amp a have evere use, it’s not a doublebass amp it’s an “universal amp” for all acoustic instrument, with a neutral sound, Perfect for double bass. I had try with a K&K rockabilly pickup and it’ great great tone and all slap sound ( click) you want due to the litte tweeter. It’s expensive but you won’t regret it. There are 2 version of this amp, 1 with a 10″ speaker and 1 with 12″ speaker.
cheers