wills1970,
Usually, the SI unit is placed at the helm because that is where you will be doing most of the general scanning or trolling to find your fish and structure on SI. With that though, most guys have another SI or Sonar/Chartplotter mounted on the bow as well with a transdcuer on the trolling motor.
It will really be your preference, but you will find yourself being able to scan with SI/DI at the helm much easier and quicker to find the structure and the fish.
You may find yourself wanting another Humminbird unit for the bow so you can network the two and share and mark waypoints on both units.
With your situation I think you will just have to decide what is going to work for you. Maybe put the 1197 at the helm on a mount so you can turn it around to to face the front.
Hope that helps.
Robert