I am converting 800 sq.ft. attic to living space. Even after insulating the roof R30, I suspect the attic could get pretty hot, so I am installing AC for the whole house. The first floor is 2,300 sq.ft. but the climate is very moderate. Just a few days a year temps reach 100F outdoor and it's almost always cooling at night.

I'll have four zones on the first floor and one zone in the attic. We'll never need to cool off the whole house. Probably attic only 80% of the time, and occasionally 1 or 2 zones on the first floor.

I am thinking at a 3 Ton unit, with 600/1200 cfm blower which I could switch from the computer. I have no experience with this stuff so any advice would be greatly appreciated.