I'm applying to MD and DO programs first time around, and doing a masters during my glide year. If I still don't get in, I'll probably reapply once more after I do some more coursework (probably perfusionist school). Then if I still don't get in to an US program (MD or DO, since it doesn't matter to me, because the difference effectively amounts to DO's having extra training in giving a great backrub) the choice becomes either Ireland or a PhD in something.