HVAC tech for furnace/coil install?

[PugnacAutMortem]

Just bought a house (ranch style, 1100 sqft on both the main floor and the finished basement) that has an old furnace and no AC unit. We have already bought the furnace and we are replacing the coil at the same time (I was told that was much easier to do up front should we want to put in an AC unit down the road which we absolutely do). My dad works for a company that sells furnaces, so we already have a 60,000 BTU unit with a 1.5/2T coil on his recommendation. I had one guy out yesterday who told me I needed an 80,000 BTU unit, a 3.5 ton coil and it would take him 2 full days and would cost us $750 just for the install. The HVAC guy's info sounded absolutely insane, so I thought I would see if anyone is/knows a good HVAC guy who can help me out with this install.

Much appreciated as always.