I was more thinking about going with some sort of ductless split with a 2 single units with 8 zones and setting that up with one to run for the top floor (4 units, 2 zones / unit) and one for the bottom floor (something like this: https://www.totalhomesupply.com/54000-btu-multi-f-max-multi-zone-mini-split-air-conditioner/p/LG-LMU540HV). 

I hear chainsaws working on my trees, my new air conditioner system working, and the ceiling fans spinning like crazy.

As a landlord of a detached property, at least you can look at the roof or air conditioner to see if you might have a surprise bill in the pipeline. 

Some other qualitative factors include weather or climate impacting maintenance costs - pipes freezing in northern climates, hail storms in Dallas, flooding in Houston, Air Conditioners in Phoenix. 

Here is the list:Asphalt cracks fix up – coding for drivewayRailing/ spindles for decks x 2 - both decks are about 8x8 feetPower wash for deckStain for Deck x 2Garage doors x 2 - need to replace bothAir conditioners – 2 - need to install new ones, the current ones are rusty and oldHeating system Furnace x2Water heater x1 - 40 gal Windows  – 2 lower level double hang 2x2 feet; 4 bedroom – double hang 3x3,5 feet; living room - 1 big window 4x4feet - steelChimney top cover x21 New toilet  1 New sink with the stopper  1 Fan for downstairs bathroom 2 bathroom fans1 Stove 1 Dishwasher Bathroom wall fix - about 20"x20"  drywall water damage next to the tubGarage ceiling fix - old damage, no leaks about  a square foot 2 Toilet needs to be tightened to the floor. 2 Filters replacement for kitchen fanKitchen cabinet missing 2 doors We are about to find all the pricing on all the things that we can buy.. but we do not know how to incorporate labor into this quote.

Do you agree if this is a typical price to replace a furnace and an ac for a 3B/2B 1400 sq ft home (Gas Furnace, Up to 96% efficient, Up to 60000 BTUh and Air Conditioner, 2 Tons, Up to 18.00 SEER, 71 dB max)? 

i was covered for the past 3 years and now the new carrier is asking me to make improvements that cost a substantial amount of money....1.) its the summer in philly and tenants have air conditioners in their windows...if i dont have a contractor install metal brackets, to prevent a falling air conditioner hazard, my coverage will be terminated. 

I’m planning on installing an electric furnace/air conditioner in both units.

I would recommend replacement of the equipment .Condenser&Coil 14/2T Up L1MAIN FLOOR PROPOSAL:Provide and Install new Carrier Comfort Series 2 ton 14 SEER air conditioner and matching all aluminum cased upflow evaporator coil.

They pay rent early and only call about important stuff like, "I thought you should know that water from the air conditioner drain is running back under the house.