Try Dan Crookston with Rocky Mountain Air Systems. You can reach him at (801) 255-6800. I have used him on three homes we built ourselves and one townhome I owned similar to your situation where he added the central AC after the fact. My wife and I have known him for almost 30 years, his work is top notch and even when we got competitive bids he was always the lowest bid. Assuming you have a pretty standard forced air heating system, my guess is this would be fairly simple and you probably don't even need to add any new ducts. I don't remember the exact cost when we had it installed in the townhome but it was pretty reasonable.
That property is located near the top of the mountain in the Deer Valley Ski Resort. The nearest interstate highways would be: I- 80 going East and West, and I-40 going North and South.
I would estimate that each Interstate Highway is about a one half hour drive from this address, and it would be about an hour drive to the Salt Lake City, Utah Airport. please do not hesitate to call me if you have any other questions.
Jess Reid Real Estate