As far as where I live, it is generally flat. We're talking probably about 2 or 3 days a months in which I would trailer 30 minutes to an hour away and just trail ride for the day. If I get a chance this summer, I would like to spend a weekend at a lager park that is 3 hours away. I would encounter some hills in that area. Annnd now my dad is expressing an interest in buying a horse in the next year or so, so that he could trail ride with me (which just means more weight to the trailer).
So I think I've come to realize that 3/4 ton is the way to go. Thanks so much for the info guys! Like I said, I'm totally new to this (I actually knew little to nothing about deisels). Great learning experience for me. :P