You might want to look into this deck from JVC.
It's an unbelievable $500 off right now.
JVC KD-S100 CD receiver at Crutchfield.com
Hell, I'm even thinking of buying one, just because of the price.
I'm not sure about the Sirius connectivity with this HU though. That's why I'm keeping my stock HU for now too.
That JVC has USB and
SD Memory Card inputs. Pretty sweet deal IMO.