New furnace/ac help???

We are in the process of deciding between two heating and cooling systems. Our house is 13 years old, 3000sq.ft. and the current furnace is chimney vented.
It is between the Infinity 96 system(96% AFUE) by Carrier with the 17 seer heat pump or a York Affintiy System (80% AFUE)with a 14 seer AC unit.
The price difference is about $800 more for the Infinity system. We live in the Philadelphia area. Any suggestions??

Is Carrier better than York or vice versa?

800.00 bucks is cheap whats to think about? All things being equal as far as contractors.

Based on what you have stated, I'd definetly go with the much higher efficency Carrier system.

Is there any problem with continuing to use our existing chimeny vent with our gas hot water heater since with the high efficiency furncace the venting will be changed to pvc venting?

Are these choices from different contractors? If so, there's a lot that a contractor has to do to make your system run right. Choose carefully. You're not buying an appliance.

existing chimney may need to be lined.