Thanks for the quick replies. We went with #1, and the servos should arrive by Tuesday evening. The dumper/loader is already pretty well balanced (it tilts at the middle, and has standard servos at both ends to load and unload, but those contribute to the weight).
The backstory on this is that the dumper was working okay with a lower-torque standard servo, but it was pretty strained and seemed like it would break at any time, so we got one with 4 times the torque figuring that it would have no problem. However, they mounted it with a top-mount bracket and there were screws on the back of the servo horn that were rubbing against the mount each time it turned. Additionally, I think it was only pressed halfway down on the spline, so it was easier to strip half the spline than the whole spline. I guess those top-mount Tetrix servo brackets aren't meant for use with actual servos because the clearance isn't large enough to attach anything to them!
Ours now has a nice, larger hole to prevent rubbing.
(We might be able to get away with one, given that fix, but two seems so much safer for a critical component of the robot.)