Thanks everyone for the responses. I'm glad to hear I wasn't too far off in my initial understanding.
We're still in the exploratory phase, so I agree with MDamerell in finding the right trailer then truck. Right now we're focusing on the smaller 5ers. Mostly rear bunkhouses under 13K GVWR. Based on that I *think* we would still be good for a 250/2500 class TV.
Chris - checking the ratio of dry-to-pin weight is genius. It didn't occur to me that the ratio of overall trailer weight to pin weight is consistent.
Cheers,
-Brian