I'll second the kenwood unit. Not only is it pretty inexpensive, but it responds well to automation and is 232 controllable. The triple tuner Antex I think was around two or three grand... not worth it for highly compressed audio to me.

Oh, and as far as getting the signal to the tuner... Terk has extension RG-58 cable. I also saw a set of balun type gizmos at the Sirius booth that allows you to send the signal down RG-6... so if you have a spare in the attic you are good to go. Haven't tried them yet but they are kind of like the Xantech Injectors were with sending IR data down RG-6 (except sirius will need its own cable, no piggyback action).

-Pete