[nafs]

Buzz, I will have the exact same installation as you described going in this weekend. After weeks of searching, I had the same exact questions as you, with no definitive answers.

That is why I am paying for a proffesional install. I live in NYC and Audio Designs is doing the labor.(I am providing all the hardware) Its costing me about $400.00, but I feel more than confident these guys know what they are doing and are going to do it right with a 2 year labor warranty. I visited there shop in downtown Manhattan and it is first rate. At the time they were installing on a Ferrari Spyder and a Bentley. The H3 will be in good hands.

As far as your components list, it seems complete except for a dash kit(don't yet know if you really need it) but scosche 1595b is for the H3, and maybe a gm antenna adapter for regular am, fm.

As for camera mounting, if you have a tow package the rear mounting bracket in the back makes a perfect location in terms of height and line of site, also is away from most of the elements.I saw this install location at my dealer. All their aftermarket installs had them in that location.

As far as existing XM antenna usage, I have read that it can be used.
Also somebody has installed the gps antenna inside the dash assembly and it works great. I instructed my installer to test out the installation there.

I will keep you posted on my pro install experience. Good luck