I concur with what others said. Have your speed managed at the TOP of the hill. Its easy to add speed, its more difficult to lose speed.
If you need to brake, I believe it is preferred to stab your brakes hard and quick rather than ride the brake pedal. The idea is that a quicker and more sudden brake won't produce the heat that a long gradual braking does.
Don't be afraid to go too slow. People might be pissed they are stuck behind you, but they will be WAY more pissed if the road is closed due to an accident.
You have a 3/4 ton truck and a relatively light trailer. You should be fine. Good luck.