You will need the structure scan unit the LSS to network the two units and an Ethernet cable or two. You will get a short Ethernet cable with the LSS about 3-4', so it depends on where you mount the structure scan unit as to the length of cables you need. If you can mount the SS unit under the dash, you will only need one cable to run to the bow graph. Buying two units will make the Lowrance less money than the HB. HB is less for a single setup.
I sell these graphs, and boats also. May have something you need. I sell Xpress and Excel, and have several used rigs too. PM me with your best deal, maybe I can save you a few bucks. You can call me anytime.
We only sell the Best. Ranger, Xpress, Yamaha, Suzuki, Tohatsu.