Reputable HVAC Business in Kansas City Area?

[Jesse Smith]

I've purchased a few older properties in the KC metro area.  Each of them came with older HVAC systems.  One furnace died over the past week, and at least one AC unit needs to be replaced.  I'm looking for a reputable HVAC business in the area, who won't try to kill me on pricing.  I'll likely be replacing a few whole systems to prevent issues down the road.  I've had a few estimates, but it seems like each of them is trying to tack on things to up the price.  There are also smaller properties - Duplex w/ 650sqft per unit, and Single Family home w/ 900sqft.  I've been quoted prices for 1.5 and 2 ton AC units.  I'm learning, but I don't know enough to argue with the professionals, especially when I get conflicting info.

1. What business have you had a good experience with?
2. What size AC units should I be looking for - my understanding is 1.5 ton AC should be plenty for my smaller properties.
3. Any general advice on replacing HVAC?

Thanks in advance for any help!  This is a big cost for a relatively new investor, so I want to get it right.