What is the deal with the Sirius add on for Pioneer head units. I have a z120bt with XM unit that I just had to plug in the wires and antenna? I am going to do another z120bt install on a friends truck and he a Sirus account. What is the deal with the CD-SB10? Do you have to have a seperate Sirius unit to run everything on the HU? Does it have to be hard wired to switched 12volt power to operate correct?

Yes and Yes.

Whats the cheapest Sirius unit out there that will allow for full control from the z120bt?

I found the Sirius SC-C1. Can I use that reciever along with Pioneer CD-SB10 and have everything good to go? The reason my friend is swapping HU is because his older Kenwood Excelon screen has seemed to go bad. Any compatibility between whatever Sirius components they used back in 2006 with a z120bt? (Just wondering before I go looking through his setup)

You need the SCC1 with the SB-10 for Sirius on the Pioneer units. Those are the ONLY current adapters. To be honest with you the Sirius interface SUCKS. Get the GEX-P-920XM for you and your friends. You'll be happier with it. I have pictures of what it looks like if u want them.

Yeah, use the P920XM tuner and get the Sirius subscription package.