We've installed a new Amana 2 stage heating and air system with heat pump. It is the ASZ16 heat pump and ACV9 furnace. If we use the Honeywell VisionPRO TH8000 thermostat, can we use the dehumidification control with the amana system?

Yes and no. You only have one stage cooling so when you run the A/C it will dehumidfy but no more control than a normal thermostat.

Your model hereASZ16 Heat Pump



16 SEER/9.5 HSPF Efficiency

R-410A Refrigerant

Amana Air Conditioners, (A/C), Packaged Heat Pumps and Central Air Conditioning (AC) Units for Home Healing and Cooling Systems. Residential and Commercial Heating and Cooling Equipment by Amana Heating and Air Conditioning available in 14 SEER and 1 (http://www.amana-hac.com/Home/Products/HeatPumpSystems/16SEERASZ16/tabid/339/Default.aspx)

This is supposed to be a 2 stage unit?

Well if it is it must be a different model number. I sent you to the location with the link. Unless the link is wrong. Google your model number and see for yourself what it has to say.