The Helix 10 SI GPS comes with the HDSI transducer.
Practical is better than purchasing two units. Just need a transducer and power cord.
XHS 9 HDSI 180 T and PC-11 plus the cable collector.
Then you would have to duplicate how it is mounted. A RAM or similar mount would be easier than another gimbal mount.
Humminbird Helix 12 SI, 1198c SI, 1198c SI, ONIX 10 SI NT, 360, RC-1