I need help in selecting new fish finders for my boat. I primarily fish for crappie on Lake Ouachita here in Arkansas. I currently have an older Humminbird 797c2. I want a bow mount and dash mount system linked to GPS. I don't need a high end system. I also would like to be able to use the SD card from my old 797 which has all my way-points for brush piles in my new system. What do you experts recommend that I buy?