Hello-
I had similar requirements when I upgraded to my new head unit, the only thing I am not familiar with is utilizing factory steering wheel audio controls:
1. MP3 file playback - Yes
2. DVD Playback (while moving) - Any will do if installed by someone who knows what they are doing. (i.e. any shop should be able to do this at no charge)
3. GPS (with a system that can be updated) Yes
4. Ipod nano/iphone connection/controls Yes
5. Can still utilize the steering whell controls ---Not that I know of
6. Needs to look somewhat stock (don't want a bright orange stereo Smile -Yes
7. Remote (for wireless control from the back seat) Yes
8. Screen that can be seen in the daylight - Yes
http://www.crutchfield.com/p_110V9512HD ... 12hd&tp=75
Has a motorized screen, so it is 1.0 DIN and will fit no problem. I have since installed the add on module for SAT Radio, mine came with HD Radio module and more inputs than I know what to do with (almost).
I have a backup camera hooked into mine, HDTV Tuner, SAT Radio, HD Radio NAV is a module you can purchase, I however decided I didn't need it. Oh, and the functionality is 100% whether moving or stationary in regards to video playback. PM me if you want any pics...
I picked mine up for much less than what Crutchfield sells it for from a local retailer with free installation.
Good Luck!