looking to buy a fishfinder gps combo over the winter to replace my eagle fishfinder. will put the eagle up front by the trolling motor. confused by so many different models. would like to get a simple one that marks the fish,location.and marks the spot and uses the gps to travel back and to different coordinents .they all seem to have more options then I can use or want. can anyone help or advise? ps , looked at some humminbirds in the 400.00 to 500.00 range