www.DucaneHVAC.com
5 year parts warranty.
I would get the optional TXV (thermostatic expansion valve) for best cooling efficiency.
I would get the model number of the matching indoor coil that the contractor is providing. The model number of the matched coil is in the spec sheet for the 14 SEER, 5-ton condenser, in the link to Ducane's website.
Good luck.

