I am in the process of putting a new heating and air system in my house, and was wondering if anyone could share their experience with me. I'm basically looking at a high efficiency gas furnace and a 2 1/2 ac unit. I have gotten quotes on both York and Heil systems, and they are within $300 of each other, with the Heil being the cheaper of the two. Cost is a consideration, so I'm likely going with a single stage unit on the furnace. My question is, are there any drastic differences that would give one the edge over the other, in general terms? The York dealer proposed using a Goodman condensing unit since it is cheaper and has a longer warranty. The second question is, is there likely to be any conflicts with using a York unit inside and a Goodman unit outside? It's pretty obvious I am a homeowner, and would like to get the opinion of someone other than a salesperson. Oh yeah, my gut feeling is the York seller would do a more profeesional installation job, but it is just a gut feeling. Anyone's input is greatly appreciated.