Whatjd- I know that a few months ago, Tweeter had a "component" style Sirius tuner in their catalog, but it never reached their shelves, as far as I have been able to determine. If you find one, let me know, I'm also looking for one.
I find that the quality of sound from my Direct TV receiver is better than my Sirius, although it is my car unit brought inside. Sirius is on Dish and either of these may be an improvement. I have seen a home Sirius receiver in the Crutchfield catalog, but it was awhilw ago.