Hey Roy, sorry you haven't received much help, and I dunno if you still need it, but an all-around amazing mouthpiece is the Schilke 51D. It's very similar to the 59, and has reliably served me for several years. As for specific corps, you'll have to ask around with current marchers/alumni. Happy huntings, enjoy the baritone!
Crown 2013 hands down. It was my very first DCI show and at the opening hit I was sold. The sheer power and clarity of Crown's hornline that year gave me chills the entire show, and the story captivated me so immensely I never got bored, and as a plus one of the few ballads to bring a tear to my eye.