If you can run gas, that is without question the way to go! I did this for under $300. 44k BTU,700Sq garage, and it does great!!! I was lucky however that my service was on the other side of the garage wall, about 12 feet to the right. I have had the garage at 70 with the outside temp around 10, of course full insulation helps. Look around and you can find these units for about 2-300, this one is a Reznor, Modines are great also. And just for the record, I do have another ball valve to shut off gas to the unit, you cant see it in the pic..... Good luck!!