They will ride a big Cylon mecha called Sauron.
Your description is epic and I would gladly pay ten bucks to see it. However, you need something dinosaurish. Therefore, I think they should ride a Sauronisaurus Rex, instead. It could stomp around emitting Polish sausage farts and flatten on Ewoks with impunity.
Luck, that's when preparation and opportunity meet. -- P.E. Trudeau