I run HDS-7 with insight for my GPS/Chartplotter and Furuno for my sonar. I guess if I had to run only 1 unit with GPS and sonar it would be Lowrance HDS. The key to the good sonar picture is the transducer.

Go somewhere like Bass Pro, West Marine, or Cabelas where you can play with a demo unit and zoom in to Lake Erie and see how you like the base map.