Mike
Understand about it being easier to replace rubrail as opposed to repaint. Just pointing out some observations. If you build the nautique style v-block, keep in mind the reason it is so large (up and down) is the bow will hit it lower and then rise as you pull out, ramp angle also will affect how big it really needs to be. Also with floating your boat on, do not winch it up tight against untill boat is completely on, as with that angle and pressure on the boards and rubrail it will need replacement soon. As for the tounge, I know Overton's offers a swing away kit, I think Tie Down Marine makes it. I would guess that you could design and build one cheaper, but definetly do your research on the design.
Just a thought, but with the conditions and circumstances you have, it might be easier to find more of a bunk style trailer (like the late 80's Malibu Skier style). They were a little longer, and usually had an extra set of bunks that would help lift the bow, eliminating the nose digging into the v block. They did use the same style v-block as the American Skier, but as I said the extra bunks would help lift. May make floating the boat on easier also. I think Trailmaster made those trailers for Malibu.
Oh yea, definitely keep in mind the tounge weight. Towing something that is tail heavy with a short wheelbase vehicle like a Jeep is a recipe for disaster. If you have never experienced this, the rear of the vehicle and trailer will start to "wag it's tail" at higher speeds violently and possibly cause you to loose control.