I am currently contracting a new home to be built. I live in Dallas, Texas and need a little help making sure my A/C is sized properly and also want to upgrade to a better unit.

I am having a 2975sq ft house built that will have two a/c units installed. I have 16ft ceilings in the foyer and the family room(350sq ft). The standard equipment is a 12seer Amana unit with a 80% AFUE(or something like that). I already know what a/c I am going to upgrade to, 14seer RCE model but am not sure of the model number Air Handler I should chose to go with it. I know I want a variable speed air handler I just don't want to break the bank and I also don't want to chose something that will be of no benifit.

Which variable speed airhandler goes with this model and also can some tell me which units, sizes in tonage, I should see for the upstairs and downstairs. I have an optional game room that is closed off in the upstairs with about 350sq ft.(included in 2975sq ft)

I know it is hard to size the units without doing a load factor but I would like a general idea to keep them honest. =)

Thanks in advance for any help,