Since you have a Humminbird unit, you are familiar with the menu system. Another Humminbird would be a good choice.
I have been using Humminbird Side Imaging at the bow with a Side Imaging transducer on the trolling motor since 2009--would not have it any other way.
In current models there is the Helix 5 SI GPS, Helix 7 SI GPS, Helix 9 SI GPS, Helix 10 SI GPS and Helix 12 CHIRP SI GPS. Plus the ONIX 8 and 10 SI in either cross-touch versions or non-touch versions.
Humminbird Helix 12 SI, 1198c SI, 1198c SI, ONIX 10 SI NT, 360, RC-1