I finally got a guy with some more clue. He wants to put a return in the one room without one, add a vent in one room, and add a vent in the hall; all while keeping a 4 ton unit. I'm waiting for his written quote later today.
I called back the first guy (5 ton, no additional vents and returns) and asked some questions. The story he wants to stick to is because his unit has a variable speed fan it can "overcome any duct problems" which is why he doesn't need to add any to do it.