A bit easier is good...for a group of 7 or 8 trucks. More challenging going uphill sounds fun, but we wouldn't have much time to spend at each obstacles, either.

Well, that's still a tentative schedule. We can still change things around. Besides, I do agree that it is a good idea to fill a tank at the nearest location to the trail. Your tank might be a bit smaller than ours, but we also have Andy whose truck consume gas faster than other 6-cyl (because of his 33" tires).