I have a Garmin eTrex Venture HC and obviously the base map is a bit minimal. I want something to show a bit more (streams, rivers, possibly a few trails) and thought about TOPO 2008 but so many bad reviews online. The NG TOPO! maps looked good but I dont think the can be downloaded to the GPS...any suggestions as to what map is good for more detail (and hopefully not outrageously priced) and one that can be loaded up to GPS?