That beast of a machine should be more than enough for you (I think it even out-specs my desktop
If you're planning on using AE CS5, just be sure that the version of Windows 7 you get is the 64-bit one.
You may be able to get away with something a bit cheaper. I gotta do a few other things first, but I'll come back and take a look around for some other suggestions.
These may also be worth considering.Dual-core i5, 6GB ramPhenom II quad-core, 4GB ramPhenom II tri-core, 4GB ram
The only issue with all of these (and the one you linked) is battery life. Unless your flight is under 2 hours long, I doubt any of these will go for that long.