The installation is fairly complex in that we need to run 220V wires that will be a little tricky and we have to do some work on the existing ductwork on the existing system.

Adding ductwork to that project for a couple hundred dollars could cost an additional $2k to $3k from a contractor.Another big savings, I got an estimate for a backup generator needing an added 20-foot gas line run.  

No duct work needed.

I recently received a quote to replace each unit separately, as well cost to run duct work to each of the additions. 

A little off topic but I was wondering if any of you have a good contact for hvac/duct work service in the Albany/ Troy NY area.

Ductwork maybe a little less, that will be about 3,000 - 4,000.And don't forget about new drain line from house to street. 

That will probably mean a little bit of changing of duct-work, based on what little I've picked up from my HVAC-Pro father in law, but hopefully not too bad.For your househack, are you already planning on tearing into drywall to have access to the HVAC ducts, or what do you have already for heating/cooling? 

One is "clean the cooking equipment ventilation ductwork".

In the kitchen below we took out about 18" of a wall to allow space for a breakfast bar (we could not take out more due to duct work).

The pipes are below the joists here as there is a soffit going in due to ductwork running along the ceiling here.