Can I integrate Sirius into factory radio on 2008 XC70??

I just picked up a very gingerly used 2008 XC70 and would like to integrate satellite radio and Ipod capability into the factory system. I've discussed this with two dealers. Not only can they not agree on whether it can be done, but neither one sounds terribly sure about what the're telling me.

So first of all - can I install sirius on this thing? I've read that the only thing the Sirius-prep adds is a DIN cable that runs from the HU to the trunk? So I'd obviously need to run that cable and add a tuner. How about an antenna? Is satellite already integrated into the shark fin?

Next - I've read that there is some super-secret connector hidden somewhere under the arm rest and you can purchase a $50 cable which you would plug into said connector and this allows full control of Ipod including use of steering wheel controls as well as charging. But, I've also seen mulit-hundred $ kits which are named "Ipod/USB adaptors". Is the extra expense just to add functionality of a USB flash drive?

Finally, if I am in fact able to install both of the above independently, can I install them together? And how does this work? Does the "mode" button (I think it's a "mode" button if I recall correctly) toggle through these two inputs along with the stock jack in the armrest?

Thanks in advance for your help - you guys seem to know your stuff...