I used a Mojave heater unit from Summit.
http://store.summitracing.com/defaul...h.asp&x=43&y=8
Works great and it was easy to plum to the defroster vents. It has adjustable fan control and it doesn't take up to much room under the dash. I think I paid about $150.00 for it. It was a very easy install.
--Mike