Some require a 100 lb. tank minimum, which we wouldn't be able to provide.
MANY do not have direct-vent features, which means you have to open a window for oxygen. VERY dangerous. Fuck that.
But... I did find some very decent wall mount units. The prices are lower. They have self-igniters and thermostats, and direct vent options. I don't know if they require a certain size tank.. will have to look into that.
But check these out:
THREE GRAND HOLY CRAP (but so nice):