Anyone see last week's episode of This Old House? If so, did you see the A/C system they were installing? They put in two condensing units outside with four zones inside, one lineset for each and split the linesets inside to go to their respective zones. The condensing units were tall, about 5 feet, narrow, about 10 inches and about 4 feet wide, rectangular instead of circlular. Each zone had it's own t/stat and outside reset controls. I didn't get the brand name but have seen similar split systems from Mitsubishi. Two of the zones were ductless, the other two were ducted. It is a post and beam house with panelized construction so, not much space to hide ducting. Looked like a pretty neat system in that you only have to hide linesets and every thing is zoned for optimum energy efficiency.