Not all radiant heat has to come from the floors, although that is extremely nice when you can afford it. A cheaper option might be to go to http://www.radiantsystemsinc.com/ where they sell units that can be installed in any room in the house.

With these electric heat units, you may be able to get your house warmed for just hundreds of dollars instead of thousands. It's at least worth a look in order to to cover all your bases before you buy something more expensive.