Got a hummingbird 798hdsi unit on my boat now.what to add a helix 9 on the front.should I run 2 transducer off the back or would you guys run 1 transducer with the switch hummingbird makes.i have a Minnkota power drive v2 trolling motor don't know a good way to mount the transducer on it.how do you guys run your units.thank you guys for any suggestions you can give me.