To draw the threads together, the answer to this is yes, you are correct. Don heads the U-17's, essentially elite 16 year olds playing against the top tier 20 and under teams in the US. Approaching a .500 record in the USHL isn't too shabby IMO. He has coached U-18's in various tournaments as well.
Personally, I think it's either Donny or Mark Johnson. On an emotional level I'd love to have Mark get it even though he wouldn't be my first choice among possibilities. Also, on Mark I'd offer a couple points regarding the most common objections:
I think Assistant of the Year, Dan Koch, could absolutely step in and continue the success of the Women's program without a hitch. He's probably going to be offered HC jobs at some point in the near future anyway.
On recruiting concerns I'd suggest that Badger fan's close connection with Mark over the long haul tends to discount what a huge name he is in and out of the Hockey world. In other words, Mark has always been the same Mark. Outside of that bubble though, Mark's stature in hockey has grown exponentially. I doubt there's a rink in North America you can go into and say the words Mark Johnson and Hockey without everyone there immediately knowing exactly who you are talking about. ( You can probably walk into an Applebee's in Cleveland and get a similar result.) Regular Badger fans are somewhat insulated from the way his stature has grown in the last 15 years in the rest of the world. There isn't anyone in hockey that wouldn't love to meet Mark Johnson and that is a giant recruiting advantage in my mind. Especially given what a tremendous person he is when you do meet him.
And lastly on coaching Men vs. Women. He hadn't coached women before he took over there, and he figured that out just fine. There's no reason to believe that transitioning back to men, with whom he spent all of his previous playing and coaching career is any problem. What he is, is a winner. Always has been. And true winning coaches are winners because they identify and over come the challenges presented in whatever it is they are coaching, whether it be hockey or (to borrow a phrase) tiddlywinks.
Which again isn't to say Mark is my first choice, but I do think these things are legitimate arguments, FWIW.