The short reply would be:
Lenovo X200 Tablet with the Multiview/Multitouch LED backlit screen. Get the ULV processor for extra battery life and the WWAN card, which would give you built in GPS as well.
Basically, what you then have is a convertible wide screen 12.1" tablet pc; a battery life of close to 10 hours with the 8 cell battery; and outdoor viewing screen that can handle pen and touch input. I don't see anything that you are asking for that the X200 Tablet doesn't provide.