ANSWER: Based on the information given I recommend the VH-SPORT RO carrier.
If the truck has air bags or air ride then that would be even better. Otherwise you might see the rear suspension of your vehicle compress. Your vehicle without can have 316 lbs motorcycle on top of the carrier and your vehicle will sit level. Additional, weight will gradually compress you suspension. The Triumph Scrambler weight 451 lbs so this will exceed the estimated carrying capacity for your suspension for a level vehicle.