I just purchased the Avic Z2 with the Bluetooth, iPod, Sirius, Color B/U Cam, GM/Onstar/Chime, and steering wheel kits. All together about $2,100.
I'm getting it installed for $ 450 next week. With the Z2, you have the Nav on the HDD, so it is more efficient that running off the DVD. Plus, your DVD/CD drive is free to be used so you don't have to get a separate drive.
Not to mention, when you insert a CD, it will be ripped straight to the HDD!!
Pretty sweet. Also, there's a Bypass to allow FULL functionality while driving.
Check out:
www.avic411.com and read up on them before you buy!
Good luck!!
-Matt