You could go for an Ibanez Promethean combo (the older style one, the new one is only 300W without the removable head, or one of the HB or Red Sub ones, if you don't mind slumming it ...
Small foot print, very small in the case of the Ibby, 500W removable head, 8 Ohm speaker out.
Loud enough for small gigs on its own and for on stage monitoring for anything bigger with PA support.
There's also the MiBass 220 with their Mi10 cab, would have a similar footprint to the Promethean.
Heard wonderful things about the Ashdown MiBass kit.
There's always one of these too >> http://www.markbass.it/product_detail.php?id=86
EBS Reidmar with one of the EBS 1x10 NEO Cabs?
Oh, and there's a few Phil Jones combos which might be interesting, although they're all a bit quiet, more intended for an acoustic environment, and may be a little hifi sounding.
Eude