I've got a Countryman ubass. The build quality and intonation isn't as good as a Kala, in my opinion, but they're a lot cheaper so you get what you pay for.
Two general things I'll say.
They are very low-volume unplugged, so unless you're happy with that, taking some sort of amplification may be necessary.
The feel of the low-tension rubbery strings is not too everyone's taste.
So, try before you buy is my advice.
I'm in Derby, if it's convinient you're very welcome to come and try mine.