I've also been curious about this and asked the exact same question on here before, but couldn't get too clear of an answer. On one hand I keep hearing guys say how the k100 beats the t75's in every way by being less scooped and harsh, but it seems not many have tried it combined with the v30's. Yes, the v30's and t75's are tried and true and sounds great in my ubercab, but that still doesn't mean the v30's and k100's can't potentially be an even better combo
For what it's worth I never liked the sound of all k100's in the Diezel cabs (too hollow, distant sounding), but they are very tight, so they could maybe be great to add the tightness to the v30's
Other than the k100's and t75's, I'd be a little skeptical if the other speakers mentioned so far will have the tightness to compliment the v30's for what it seems like you're looking for