Humminbird 597c hd - di work ok can use on trolling mtr as well as transom, gives
good down image

Humminbird 798 c hd -si work ok for side image - best used on transom - need
to be running 3-4 mph area for best results vs slower speed with down image 597

Are now at workable pricing vs couple years ago.

Best also make sure you also have "Navonics Southeast chip" run about 140.00
extra. Has good contour lines for most lakes in Florida.