Sirs: My mother's home is 40 years old; is presently heated with an oil furnace & cooled with a heat pump A/C unit. The home is single story with a full, unfinished basement and has 1800 sq ft that is heated/cooled. Over the last week the A/C has been in the process of failing. The home is presently used as a rental. The property manager A/C rep has recommended replacing both the existing units with a single 3 ton American Standard 13 Seer R-410A refrigerant heat pump. They have indicated that an electrical capacity upgrade will also be necessary. The home is located in the Piedmont region of NC, north of Charlotte. Questions:

1. Please comment on the American Standard brand versus Carrier & Trane -- both of which I am familiar.
2. Is a 3-ton unit appropriate?
3. The duct work is also 40 years old. Should we consider upgrading to a better insulated duct work system?
4. What amperage upgrade would be necessary if it was dedicated solely to the heat pump?
5. My brother is leery of heat pumps with fans facing up because of freezing potential. Are side-facing fans superior?
6. What sort of warranty would be standard?
7. If it is permissible under forum rules, I would like to ask, roughly, your estimate of the cost for the equipment and installation labor for the reccomended system.

I appreciate your input; we have near zero knowledge on this topic.