Bow transducer will mount on the trolling motor. Im not sure about the Gen 2 thing, wish I were more help there.

Your HDS 7 should have come with 2 transducers. Side imaging, and down imaging because lowrance has a dedicated down image puck. Both of those will be mounted close together for that unit at back of boat (from the setup I think you are describing). And then the separate graph that has downscan will be on bow and transducer mounted on you trolling motor.