well i'm listening to dubstep right now so anything involving moar bass sounds like a plan to me.
seriously though I think it could sound good, so long as you aren't too dead set on achieving perfect integration. i played the speakers + sub game for a while (my speakers were full size though, the 22L) and was generally satisfied with the results. i haven't tried my sub with the 63s, i should give that a shot.
splitters should be fine, that was how i ran my sub + speakers setup: two splitters on the preouts, one to the sub, one to the power amp.