Forced air is the (probably) best way to do central cooling in residential settings. Since you've got the ductwork for cooling, you might as well use it for heating as well.

Modern forced-air furnaces are very efficient. I've got a 93% efficient, 2-stage [link|http://www.trane.com/Residential/Products/Furnaces/XL90.asp|Trane XL90].

Open fires are terrible for heating homes. Unless you're using a modern stove or fireplace, they suck inside air in for combustion so you need a leaky house to have sufficient air to feed it. But that's the opposite of what you want for efficiency. Plus, there's the issue of how you distribute the heat through the house...

Cheers,
Scott.