I hope they calculated the size of furnace needed from your square footage, insulation, windows, etc. They should do a professional calculation to determine the BTU needed for your home and for your climate.
You did not provide many details to go on. Did this estimate include runnung new ductwork?
My friend got a new Lennox furnace about 8 years ago and he was not happy with it. However, that's only one opinion.
Look at Trane and others. I think Bryant is part of the carrier line, and the low end part, but I could be wrong.
Just remember, don't buy the bottom of the line to save a few bucks.