Yeah, TB isn't an option on Knutsford as far as I'm aware.

To the OP. What I would do would be to rent a car in Mobay, drive the north coast road (in good shape, decent place to get the feel for driving in JA), stay the night in Ochi then move on to Portland. Stay a whole day and night in Portland to explore and enjoy the scenery. From there to Kingston, tour for the day and stay the night outside of the city, maybe a Blue Mtn trip... From there head down south coast hwy toward TB, stop at Little Ochi for some seafood and spend the day exploring, then on to TB to stay the night and the whole next day (again to explore, it's well worth it). Then head up into the hills to visit YS falls, Middle Quarters for some peppa swimp, stop at Bluefields on your way back toward Negril, maybe stay the night in Bluefields. Then on to Negril where you can enjoy the rest of your trip.

Fin.