I live in the OKC area - 2000sf ranch w/a 9 yr old Goodman AC & Janitrol Gas Heater. The AC unit is always iffy - if it makes it thru the summer - the Gas furnace does OK. In getting bids - I can go with a 4ton 13 SEER builder's model Rheem (corsair/weatherking) that still uses the R22 or step up to the Rheem model using 410a Freon... or for about $800 more - I can go with a Bryant Evolution System (180ana048) 16 Seer 2speed AC & 94% HE (355aav060100) Var Speed 2 stage gas furnace. Comes complete with Evolution Programable Thermostat (systxbbuid01). I am leaning towards the Bryant system
BTW - Thanks to all who participate in the forum. There aren't many sites where a "everyday" person can get some education and common sense approaches to a big purchase.