Minkota/Humminbird dilema

I have an approximately 6-8 year old Minkota and Humminbird with Ipilot link.  Just upgraded my console unit to a Helix 9 and love it.  Would like to upgrade the front unit but am thinking I have to changeout the entire trolling motor system as well since the transducer is built into the head.  Am I correct?  Any thoughts/ideas?  If I do this is there value to what I am pulling out of the boat?

I am dying to get the sidescan onto my trolling motor.  It makes a ton more sense to see what is in front of you than behind if you are scouting.  But of course the 360 is the ultimate answer.  

You shouldn't have to replace the trolling motor as long as you get a helix unit with only 2d sonar.