i am currently using a 997c and a 917c, both are great... definatley do not mount the side scan on the trolling motor... several problems arise here, when it turns, the picture becomes slurred, same problem when you turn the boat too fast, even with it mounted on the transom..... next problem, i don't know how fast you can troll but probably not fast enough to maximize the use of a side scan, it is designed to be used at idle speed, you can then mark way points while moving and go back to them later, it is NOT used while fishing, as a matter of fact, it makes a loud clicking noise that i have found does affect my fishing, no matter what humminbird says, it is best to turn of the side scan while fishing

if you do buy one, mount the transducer to the transom (be sure you motor does not block its field of view), and mount the unit on a gimble mount so you can turn it around and view it from the front of the boat, or buy another unit that it can communicate with to mount in the front... this is the way to do it but requires a lot more money... if i were going to buy only 1 unit, definatley mount it on a gimble and be able turn it around so you can troll to your waypoints

if you would like to give one a test run, i fish barkley on a regular basis and anyone is free to come fish with me a day to take a look at the unit... pm me for contact info if you are interested