I went through the process this Summer when I bought a new furnace/AC and received great info from the board. I selected Luxaire with is owned by Johnson Controls. JC also owns York. I am 60 and not sure how many years I will remain in my house. I did not want the very best, not did I want low end or middle of the road.
Almost all furnaces and AC systems use the same components that are made by various manufacturers. Probably the most important thing I learned, is that its important to have great installers. It can add, or subtract 5-10 years to the life of the system. Make sure you get a 10 year full parts and labor warranty.