Do you need to purchase both tuners to get the services? I know with Sirius you do, but is XM built in? Pioneer's interface is built around XM correct? If so what tuner units to you recommend?

i beleave sirus and xm merged togeather so if u but the gex10xmt then u will beable to get sirus aswell..not a 100% sure tho

Any further info on this?

I believe both XM and Sirius offer a "best of" add-on package you can purchase if you want. It includes a handful of their most popular channels.

Ok so basically you need either the Siruis tuner or the XM tuner. Got ya

Yes but keep in mind, if you get a Sirius tuner you cant expect to get all of the XM channels, the same applies for buying an XM tuner, you cant expect to get all of the Sirius channels.