I have never bolted on any extras on the Concours that were electric. Does the Concours have spare wires to wire electric extras, or must you use a relay? The grip heaters could make for warmer rides. I need to look into this more.
You also have to be concerned with overloading any particular circuit if you run the lights off an existing used circuit. You can use the the existing circuits to trip the relay, since that does not use much power, which runs the power for the lights either off the battery or a added on accessory circuit like the ones from Murphs.