Forced Air or Forced Air with Central AC

[Kenneth Yuen]

I just bought my first owner occupied duplex in MA. I'm considering replacing 2 of the dated forced air oil furnace with a gas furnace. I would like your input on whether I should update it to a gas forced air or forced air with central AC. Central air will be an added expense. I'm not sure if it will be a benefit for a rental property. Ducts will probably need replacing as well. If anyone has gone through this process, I would love your input. What is the average cost for such an install and is Mass Save a good resource to look into? Any benefits to switching to gas for a rental property? Any cost saving tips? Thanks!