Mo@#$%^&* ..need A/C and Furnace replaced

I'm looking at Heim units.. 16 SEER a/c 3 ton scrool compressor, outdoors temp sensor .. and furnace is a two stage, variable fan, wifi thermostat, 96.5 % efficiency .Heim...(2400 sq. ft. house) this estimate was much better at $8300 with air humidifier and condensation pump, hardwired fire/CO 2 sensor (mandatory) and outdoor vent kit .. warranties are excellent...also got rebates for thermostat and furnace.. I have five estimates and they were all over the place.. some guys think you just fell of the turnip truck..( like the first guy)

I've been doing some investigating myself into heat and A/C units also..there is only like three or four major manufacturers for all these units.. so pick and choose which items your looking for and pay more for some names, which are no better than other units made by the same company. Warned by all to avoid Carrier because in the event they go down, getting parts is a hassle. Can't figure why when they make other brands under there name and they can get parts for those quickly. ??

Someone here said pick installer wisely and that is what I have read countless times. >>>> Installer is as important as units you choose. <<<< Installed improperly, even the top of the line units will not function well.