I go tomorrow morning to get everything serviced at the garage. They specialize in vehicles over 5 tons only. I've printed out the specs that you have provided. If I have to bite the bullet and put in heavy duty sway bars in the front / rear and also new shocks ... gulp ... so be it. Nothing can ruin my trip more than stretches of "white knucks".
I knew something wasn't right with the rocking and to be honest it was making me a tad nervous in the multiple lane city traffic.
Thanks for everyone's expertise. I'm sure I'll be back again looking for help in the future.