My furnace (Rheem 80% efficiency 3.5 ton?)and air conditioner are 18 years-old, the flue venting is poor (75 feet of horizontal and vertical run), blower motor is rusting etc. I'm in the process of deciding which model I should choose to replace it with - the mitigating factor is that I don't plan on being in the house more than another 5 years before selling it and any unit I would get would have a transferrable lifetime warranty on the heat exchanger and 10 years on the coil and compressor. Assuming both units installed are the same price which would you choose?

Furnace: Goodman GMV91155DXA, 2 stage variable speed 115,000BTU
Evaporator Coil: Goodman CACF060D2A
Air Conditioner: Goodman CRT42-1 13+ SEER 3.5 Ton

-OR-

Furnace: American Std AUX120C960, 1 stage 3 speed
Air Conditioner: American Std 2A7A1042 11 SEER 3.5 Ton