Getting back to point .....
I think a built in mega transducer with SI and DI on the trolling motor sounds nice but it doesn't compare to Garmin Livescope. By the time you add the cost of a new trolling motor and then knowing HB the built in Minn Kota transducer will only work with their latest Mega+ units I'm guessing your looking at investing 4 to 5 thousand dollars.
Think I'll just stay with my 2 year old Ultrex trolling motor and my 12" Garmin with Livescope.