I would suggest either a Garmin, or something from lawrance. I have used a Garmin GPS 12 for just about 10 years now. Garmin makes a great product, that is really, really user friendly and easy to learn. Now, mine is a little older, so I don't have the map things that you are looking for. However, their newer models do.
The other that i suggested Lawrance (might have the spelling a little off) I have a dash mounted version on my boat. I know that you can download maps to it. It is completly computer downloadable. These too are very user friendly. I trust my life with the Garmin in the woods, and my life with the Lawrance on the Ocean.