some things to think about.
As a 5 year subscriber of sirius I have gone through 2 units from them.
The first one was a kenwood without a built in FM modulator.
The second was
Sportster 4 Dock & Play Radio + Complete Vehicle Kit Sportster 4 Dock & Play Radio + Complete Vehicle Kit - Shop Sirius
The Kenwood I had, I had to purchase a FM modulator.
The sportster 4 dock has a built in modulator.
The problems I have had.
Since I live in the southern part of Texas you have a choice of country/tejano or christian music.

Hence why I would pay for sirius.
BUT... there are so many stations it is hard to find a clear enough station in the lower bands of the radio that the sirius unit connects to.
So I get static on most bands I choose to select.
Last weekend I opend up my 2005 mustang with the shaker 500 system and could not find the input that the sirus output unit had. The Sportster comes with an output wire to reach nearer to your antenna and still I get static because of these holy FM stations.
So, I may end up having to buy a higher power FM modulator.
to answer your question.
No I did not see any on the back of my shaker 500 that are like the output from sirius units.