The best drum room I recorded in was also the tallest. It had a 26' ceiling with wood diffusors on it as well as a giant kick-ass bass trap in one end of the room and a well mixed variety of wood (mainly)/glass/stone/sheet rock with soft surfaces thrown in. (And thick curtains over mirror/windows that you could open/close to change the hi-end response of the room.) Quite nice!
Daniel, I'd be happy to get only the garage part. Tell me if you want to sell it... It might cost a bit for shipping though.