Jdr

Here is my general spec sheet for new system.

both outside and inside units should be replaced to have a properly matched system.

15 SEER, 12.5+ EER, 9 HSPF
best matching VS air handler
full BTUs in both cooling and heating for your rated size
R-410a refrigerant(same as Puron)
scroll compressor preferred
electronic demand defrost preferred
thermostat with "dehumidify on demand" feature
staged backup heat strips
new and correctly sized refrigerant lineset
10 yr warranty on parts and compressor

you want a thorough inspection of your ductwork system. size, overall condition, supply and return lines, insulation qualities, leak test, etc.

any hot/cold spot issues in your home should be addressed.

My personal recommendation is Trane/AmStd, Rudd/Rheem, and Carrier/Bryant.

Depending on your location, I would not purchase a new system that did not have electronic demand defrost.

I would look at Trane's XR13 that has good performance/efficiency numbers if paired with correct air handler.

IMO

The sister to the Trane is American Standard. It might be a bit less cost.

jdr4170:

Taking a big leap of faith and making the assumption that the 2 ton heat pump your replacing was the correct size your faced with many options.

On the less expensive side you could go with a 13 SEER (basic minimum new unit SEER being sold) with a matched single speed airhandler. Probably in the $4,000 ballpark. As noted above to increase efficiency and comfort go with tigerdunes recommendations.

The least expensive option might be replacing just the non working parts of the present system but unless that system was relatively new you'd be making a really bad decision.