You should go for the dedicated GPS route- i'd recommend the old trusted Garmin cs60x
Got all you need, waypoints, basic map, you can use it with one hand (gloves), colour illuminated screen, runs on 2 AA batteries for a long time, and BUILT IN BAROMETRIC ALTIMETER.
These are old tech, but reliable- you should be able to get on dirt cheap on Ebay.
The interface to the PC is via USB cable, and you can use free software to analyse tracks, plan routes, etc..
Check out GPS Trackmaker- www.gpstm.com