Expy XM radio install

2005 Eddie Bauer Expy, 6 disc CD internal. I have seen several XM modules that "say" they are for this radio, but several have "exceptions" for fitment. Some say they will NOT fit the internal 6CD unit, others don't mention it. My radio is the "factory ready" radio with the SAT button on it. What do I need to install XM, and where do I get it?

Guys.....I don't want to buy something, disassemble my dash, and then find out it won't work and have to return it.

Can anyone help me with this??