I have flown about 70 hrs with a leg-strapped Skymap 2. It runs for 4hrs from non-rechargeable AA batteries, or a lot more from an external battery pack. It has a permanent location text e.g. "3.4NM NNW of Southampton" but you cannot fix the reference for that text (and use it as a "DME"); it just picks up the nearest item from its database (but you can qualify the category in the setup menu).
The Skymap 2 is the only GPS I know of which is really suitable for leg mounting; this may be relevant if you are renting.
I used to program it with Navbox and then it's really great.