The power wiring should be the same ...
The SI xducer used on a dedicated DI unit will work ... But not satisfactory ...
This is because the SI xducers do not have a dedicated "down pointing" DI piezo ...and the DI imaging (in the HELIX DI) will be getting its echo data from the right SI piezo in the SI xducer (which is "pointing" 60° from horizontal to the right side) ...
The HELIX DI will come with the XNT 9 DI T ...and it should be used ...unless there are plans for a trolling motor application ...wherein the XTM 9 DI 25 T should be used ...
Rickie