Thinking along the same line as Pat, does anyone here own or use a Roland BA-330 portable amp?

Yes, they are pricey, but the reviews look great, the size, portability, and most of all, the enormous flexibility looks terrific for all sorts of uses and combinations, which sounds like what the OP is after. Wouldn't need a mixer, FX or much of anything else... and of course, for that big bass sound, it can always go out to a bigger amp or PA. It would certainly meet all the needs, present and future, of the OP... take a look: http://www.sweetwater.com/store/detail/BA330/

Anyway, I am really asking for reviews for myself... Maybe I can be busking again on the Santa Monica Mall -- altho I may not be able to afford to pay off the cops.

Brad -- My FAWM