We just purchased the old school 798ci si (not HD) and are beginning to realize how much your fish finder controls the purchase of your trolling motor. Oops

We want to upgrade to a Minn-kota Terrova with iPilot and Autopilot. Will the older 798 (non-HD) work with these applications? And what is US2 and how does it work with 798?
I should mention that we only want one unit in the boat and preferably at the console.
Thank you for any input.