Hi Steve I am looking at the same thing but for different reasons. I race a 30 footer and need adjustable cars. Currently I have T track and one car. I am trying to decide if I should replace my track and go with the Harken CB track and adjustable cars system.
In your case just cruising I think as long as you select a track and car that suits the size of vessel and sails then you should be good. Two cars each side make changing between two sails on the go eaiser but is not necessary for cruising.
Eagerly waiting for spring.