I have a couple Ps both with Labellas---I wouldn't use anything else.
I also have a B100R. It's a killer combination you have there. You will be in classic tone territory instantly. I've even used that amp at sessions where a B15 wasn't available and nobody blinked. Damn close.
If you haven't used flats before, once you get into that tone, you'll find that you think about "cutting" through the mix a bit differently.
That sound (especially for the music you describe) simply just SITS right in the mix, and therefore speaks out more defined and clearly than a roundwound sound often does.
The note decay, the built-in tone of that bass/string combo--it's like they already sound "produced" with very little EQ fiddling. It gets you in that sonic space in the mix just right.
And I say that as a reggae/dub/hiphop producer as well as a bassist
I can't think of too many things as fun as thumping thumb/palm mute on my labella-strung p to a deep reggae groove!