The Cutlass version that you are thinking of for Bounty hunting is the Cutlass Blue which should be on sale this next Friday. (as best as I can guess)
I could be wrong, but I remember reading that yes you are correct, the Blue is definitely "the" Bounty Hunter ship. The blue would be a better suited, better shielded and far more capable as a dedicated bounty hunter overall ship role, and that it would also hold the most prisoners, though they mentioned that the Blue and Red will not be modular like the Black and cannot be stripped down to a blank ship template the way the Black can and have your Black be re-fitted for other roles like BH.
If I am remembering correctly, I believe one of the devs said in an interview that there are discussions to implement various module types for the Cutlass Black, seeing as the Cutlass Black is the "empty hull" template so to speak for the Cutlass hulls, same as the Tali Base is the blank hull to the Bomber. The Black also makes sense as a BH ship, with low signature engines, side doors etc, she is supposed to fly fairly stealthy and off the radar and allow for fast, easy boarding of other ships. The Blue I do not think will be nearly as stealthy in sneaking up on it's contracts but will have better scanner capabilities as well more prisoner cells, and better overall ship combat survivability due to advanced shields etc.
If this is the case, the Cutlass Black bounty hunter module will alow you to run BH missions, but not nearly as effectively as if you were in a Cutlass Blue (or now an Hawk I suppose) but would still make a more than capable Bounty Hunter ship for those that want to own a multi-role ship.
My hopes are that the Cutlass Black will be usable for BH, but if I am wrong and there will never be a BH module for the 'Black then that's cool, I'm happy to be a dropship / cargo-runner / support / dragonfly or nox carrier / Alcohol/Beer runner or whatever role is needed for the Org
...wonder how many cases of beer a Black can hold