Inexpensive Heating Option For Garage Studio?

Hi, I'm in Seattle and I'm just starting to think about my 2 car garage -temporary- studio conversion (see my other thread viewtopic.php?f=2&t=13845&p=96394#p96394 ). I'm actually doing 'computer' work in the garage now (freezing my arse off) whilst contemplating what's to be done. I'm right next to the house natural gas furnace, but it's illegal (and probably totally inefficient) to just run a duct off that.) My g/f and I would like to have a separate heat source for the garage. So since I -am- freezing -now- I was considering getting something like -this-: http://www.sears.com/shc/s/p_10153_12605_00917258000P They -claim- to be inexpensive and I know they're dead quiet. Anyone use this sort of thing before. Since the garage is so drafty, I doubt that air circulation would ever be a problem. Any other ideas? I mean, I -can- do a proper setup, but if this is something that can warm me up now -and- be usable for the future, I'd consider it. The other thing is that I don't want to put a lot of effort into ducting from the furnace or baseboard because, as I say in the other thread, I am NOT going to be here past the next 2 years. TIA, ---JC