I have received a quote from a highly reputable contractor that I have a long history with for a new Carrier Infinity 96 System. It is to serve a 2 floor colonial home with one unit and a series of new ducts and dampers. There will be 3 zones, 1 downstairs and 2 upstairs (1 being a new addition over a garage). Is this better than 2 separate systems 1 in the basement and the 2nd in the attic with new duct work?

Additionally is carrier a better system for this than Rheem, or Armstrong?

Thanks,

SAK