I need opinions on the following I will more than likely be purchasing this unit (it is used)

This is what I was able to research:

Gas- Furnace [GY8S080B16UH11C]

Condenser [TCGF36S4151A]
York® Latitude™ TCGF Air Conditioner, 3 Ton, R-410A, 14.5 Seer, Microchannel Coil technology

Air Handler [MC43B3XH1H]
This is the only thing I could find on the MC4B http://www.master.ca/documents/York_...Guide_0710.pdf

Whole House Air Cleaner Merv 13

Unit is sealed, pumped down, and captured he also told me to tell the installer
King Valve/closed/sealed "

He is willing to sell it to me and offer a warranty and return period if a licensed installer installs the system. The warranty has not been registered and I was told by an installer that he could register the warranty for me.

This system was a matched set and only saw approx 1 month of actual use.

By the Grace of God I am getting a deal on this installed for 2 Grover Clevelands. Is the above unit a good unit? I am going to get it anyway the guy selling it said it was a good system and he is willing write up a return contract on it.

Can I get buy with using the same flexible duct system that I currently have (there was mold and mildew in my old handler) or will that have to be replaced?

Thank you,