As a fellow boat guy and new 1000-3, 700-4 owner, I have been looking at GPS units as well. Still debating if I need a terrain map, I just don't want to get lost and I want to be able to find my way back to camp. I am using my Garmin GPSmap 76CSx, a hand held marine unit.
I simply start a track, mark some way points along the way and save the track. I do this each time I go out on 16K acres. When I feel I'm lost, I just reload one of the tracks, and follow it back home.
I see you're from FL - Have you ridden Ocala? We just did and really enjoyed it.