Did you get complete model numbers on all your quotes? If not then they are not complete. The model number will indicate the size. You want the equipment to be the proper size. Are all the quotes providing the same work? Did any indicate the brand and model of the coil? Do the quotes include a thermostat and if so what brand and model? What type and size (1 inch vs 4 inch) medial filter will be provided? Will the line set be replaced or just flushed? What is the warranty for parts and labor?

Are these quotes from 5 different installers? If so which one did you like the best? Which one spent the most time looking at your equipment? Did any take any measurements and do calculations? Did any measure the duct work and inspect it for problems?

The three brands you have listed are all equivalent. The Bryant is the low end Legacy line. The is the reason it is the cheapest cost. If you have the funds and plan to live in this house a long time I recommend upgrading to the Preferred line if you like the installer. The AC is listed as "up to 16 SEER". The furnace you were quoted is single stage. You will probably get 13 or 14 SEER. The installer should provide an AHRI certificate indicating the actual SEER rating.

The Amana is equipment is high end. It is a 2-stage AC with a variable speed furnace. If you have suffered from high humidity in the summer, then a 2-stage AC will give better humidity control. I think it is worth the extra money. The Amana will likely achieve 16 SEER and might qualify for a local utility rebate. If available you should factor that into the final cost.

4 year old post.

I missed that. Perhaps the original author will respond with which equipment he chose and if it worked out for him. Buying equipment solely on brand name and prices is not the best way to purchase HVAC equipment in my opinion.