Gday bigbrian47
we use Garmin colour gps.Garmin use there own mapping system (blue chart) but most other gps use C-MAP. Many people have different opinions about them using Blue Maps but we have found them to be alot more detailed then C-MAPS check a unit with C-MAP and a Garmin and decide for yourself. Iam told rescue planes and helicopter's use Garmin as well. The Garmin has everything you can think of.colour $2100 black and white $1600 go and check it out