If you are buying new, looks like you will need a MacBook Pro 17"
Apple - MacBook Pro
By the way, nothing compliments an Airstream better than a shiny silver Mac laptop!
I've got the 15" Powerbook and use it for playing back (full screen) tv shows purchased on iTunes. You can download these shows before your trip or otherwise you will need access to a strong WiFi signal (or other internet connection) on your travels.
The Mac laptops come with DVD drives, so you are all set for watching DVD's.
If you regularly camp in places with reasonably strong WiFi (RV Parks) there is a new device that will stream tv shows directly from your house to a remote laptop (Mac or PC). Its called Slingbox (
Sling Media - US Home)
For example if you have a Tivo or other DVR, slingbox will allow you to access the menu remotely and play back shows to your laptop. Again, you will need a reasonably strong internet connection. I haven't bought a Slingbox yet - I've demo'ed one and was very impressed. It can scale quality of playback to the strength of your connection - very slick imho. This will be on my 2007 "wish list" (along with stuff like a generator, but that's a different thread all together!).
Mac's are pricey - but well worth the investment - good luck!