First off let me weigh in on the Trane v/s American Standard debate, there exactly the same units. If you stripped the tags off and laid them out in peices you could never tell the difference between the two... I am a Trane dealer and also own an American standard dealership the equipment is exactly the same. Yes there is a price difference between the two, Trane does a lot of national advertising American Standard doesn't.
I will throw out one more point for the OP to consider though. DO NOT GO R-22 FREON!!!!
Under the terms of the Montreal Protocol, the U.S. has agreed to meet certain obligations relating to the Phase-Out of HCFCs by specific dates.
January 1, 2004:
In accordance with the terms of the Montreal Protocol, the amount of all HCFCs that can be produced nationwide must be reduced by 35% by 2004. In order to achieve this goal, the U.S. ceased production of HCFC-141b, the most ozone-damaging of this class of chemicals, on January 1, 2003. This production ban will greatly reduce nationwide use of HCFCs as a group, and so the 2004 deadline had a minimal effect on R-22 supplies.
January 1, 2010:
After 2010, chemical manufacturers may still produce R-22 to service existing equipment, but not for use in new equipment. Air conditioning and heat pump manufacturers will only be able to use pre-existing supplies of R-22 to produce new air conditioners and heat pumps. These existing supplies would include R-22 recovered from existing equipment and recycled. It is likely that rather than depend on this very tentative supply of R-22 for new equipment, manufactures will instead utilize R-410A in all new units.
January 1, 2020:
Use of existing refrigerant, including refrigerant that has been recovered and recycled, will be allowed beyond 2020 to service existing systems, but chemical manufacturers will no longer be able to produce R-22 to service existing air conditioners and heat pumps.
So in 5 1/2 years your new R-22 condenser is pretty much non serviceable... we have already seen R-22 prices 5-6X what they were in 2009, and although they have settled out i do expect they will go up again. Also the "dry" R-22 condensers out there are tytpicaly 10-20% more than the equivalent R-410a condenser in wholesale cost.
Ok, now if you have an American Standard / Trane indoor coil or airhandler it can very easily be converted to R-410 by adding an expansin valve kit that they offer for just such an instance.
long story short buy the new condenser in R-410 and have them add the expansion valve. better to throw away a 100 dollar valve when your coil goes bad than to have to replace the condenser again 7 years down the road when your coil goes bad....
scotty