Telematics unit and others in trunk

I am rebuilding a crashed 07 650 that had the electronics in the trunk stolen. I am trying to replace them as inexpensive as possible which includes ebay and other sources. My problem is that I am not sure what I need to replace and what I can retrofit. In particular, I need the telematics control unit. I find from the parts listings that there are both GSM and CMDA versions. Can I use either? Which is better?
Also, do I need the standard blue tooth antenna as well as the backup antenna? Both are shown on the OEM parts listings.
Does anyone have a photo of what goes in the drivers side trunk space of their 650 that you can post? That would help greatly.
Thanks,