I found that in my 08 that the Sync components were not just in the radio/navigation head but also in the console. I don't believe the 07 offered the Sync option so you won't have everything you need.
I may be wrong, but I believe your best bet would be to put in an aftermarket unit with voice recognition. Crutchfield.com includes wiring harness connectors and good instructions to make the switch to the one you choose. They have a pretty good selection
Ditto on Crutchfield. They're a bit more expensive, but they provide everything you need and the last time I checked, they have live support for your install questions.
