I applied to several of these and was fortunate enough to get interviews at 3 of them. The application requires a separate PS explaining why you want to do a combined program, as well as LORs from medicine faculty. I had better luck with these programs, but that may also be because I think I had a better application for med-derm rather than them being less competitive. As far as the training goes, check out the UWisc website, it's pretty much self-explanatory.
