Another DVD/NAV question

Hello...new Tahoe owner and new to the forum. Just purchased a new '08 Tahoe LT2 with bose stereo system. The radio is basic including single cd/mp3. I would like to replace the radio with an OEM DVD/Navigation system and either a flip down screen or screens in the headrests.

I browsed all the nav threads, but couldn't find all info needed...can anyone answer:

(1) What is the part no. for the OEM nav/dvd unit (I have the bose sound system)?

(2) Any thoughts on ebay vs. dealership? If I go ebay, how could I get it installed?

(3) Any thoughts on a flip down screen vs. headrest screens?

Anyone else go through the same upgrade? Any further thoughts or lessons learned?

Thanks in advance for your help!
Steve
Glen Allen, VA

Given the choice, I would go with headrest monitors. I don't like how the factory drop-down screen blocks the view out the back window.

I had the stock nav unit and replaced with a Kenwood DNX-5120. The stock nav maps are not great, the Kenwood uses Garmin and I am much happier. Also with the stock nav, ipod control is not available unless you use aftermarket box to hack in. Problem there is the factory unit does not have enough memory to display everything in ipod so you end up having to use playlists. Also there is no bluetooth with factory nav, without another additional aftermarket solution. In my opinion if you want ipod, nav, and bluetooth you are better off with a aftermarket head unit.

If you still want factory nav, I may have one available. I sold it on ebay a couple days ago and still have not received payment. I am going to wait a couple more days for payment but if I dont receive it will be up for sale again. PM me if you are interested.