Mileage is going to be 95% throttle hand control and cruising at speeds under 80mph/130kph.
That said, sadly, your desires are contradictory, max torque is a richer than 13.5 AFR, max mileage will be around 15 AFR.
A skilled tuner, like Nev, can get you a good balance but your mileage is going to hurt from having the side car no matter what.
Penner's tune will do good things for your bike from the Resources section, his tune is well optimized and should yield a little better than stock tune mileage with it's moderately advanced ignition timing.