Just my two cents - you are asking about going from a vest style to a back inflate. My wife wears a Lady Nighthawk from Scubapro. At first she hated it until she got used to using the trim weights as a back inflate wants to tip you forward on the surface. I mostly wear a Hollis HTS with a wing. But, I also wear a Nighthawk for teaching. BEFORE shelling out a lot of money for a component system, please do yourself a favor and try the back inflate without the BP&Wing configuration (rent, beg, barrow or steal :)
- just to make sure you are on the right "comfort" road.