I'd look at the MarkBass CMD112, GK MB210 & GB 6.0 12T combos as these are all light, powerful enough on their own & have the capacity to add a 2nd cab for larger venues. The other combos suggested don't have that option I believe. Of course just going a separate head n cab by any of the makers mentioned by everyone would also do the job.
Lefty 4,5,6 string basses with GB, GK & Nemesis rigs. GB Club#376, Steinberger Club#5, Headless Club#64