I blew it when I built my garage. Radiant Floor heat is the way to go if you are going to heat it all the time. Nothing like laying on a warm floor. I have been looking at electical mats that will keep my feet warm but I don't know if they will do the job in New England. I guess a propane space heater is the way.
If you have ever been over to the Garage Joural there is alot of good information on that site.
http://www.garagejournal.com/forum/index.php