Thanks everyone! I guess I will never know if I don't try him out :]
I emailed the owners, and they said that he does buck, but with his head in the air and not a buck like he is trying to get the rider off.
Even if it's a little buck though, for a big horse, a little buck could feel pretty huge! haha
Maybe if I choose to go meet him, I will just get to know him the first time, instead of riding. Or, maybe they would possibly give him on a couple week trial. I find it tricky to test ride a green horse that doesn't know much, when I'm nervous about the test ride, and the horse and I don't know each other (or trust each other not to do anything crazy!)
franknbeans -- I guess it wouldn't hurt to try reining anyways! I just like it for the fun, and who cares how many people would be laughing at us!
Trail riding totally makes sense too, their backs are probably barely just getting under the branches, let along the rider! haha
The tack could also be an issue, I would definetly have to sell my precious saddle :[ And, hay... that would be pretty expensive for a big guy.