We suggest a Cummins QSM11 rated for 715 HP would achieve the speed you are looking. We have also put a C12 Caterpillar and that would also get the speed you are looking for just a much heavier and pricier engine.
Usually when we weigh a boat it is for the massive sum of $0.00
The most we've ever spent is $5.00 to weigh a vessel on the trailer, then the empty trailer is weighed for no fee.
Not exactly a deal breaker as far as price goes