[turbo6bar]

The Copeland scroll compressor is top shelf.

All major brands are good, but the real key is quality of installation. The most efficient unit on the market will give poor results if you choke it with insufficient ductwork.

Ask friends and neighbors for references.

If I recall correctly, R-22 will not be sold in new units after 2010, but the freon will still be around until 2020, when production stops. If you go with R-22, you should have no issues with future service. Puron is just the latest and greatest. I don't think it is better than R-22. It's chief purpose is reduction in impact on the environment. Puron(R-410A) runs high pressures and requires more stringent installation protocol, so expect the labor/installation cost to be higher.

I focus on best bang for the buck, so I would shoot for SEER-12-14 with R-22 refrigerant. The Copeland scroll compressor is a great piece, but a quality install with any other compressor trumps the Copeland with lousy installer.
jurgen