Jeff Allen is going to go before #45 as a tackle. He played both the left and right side tackle at Illinois as a a "weakside" tackle, because they flipped their offensive linemen around depending on the play. That kind of versatility is going to attract a team desperate for a tackle (which is about half the league).
As far as a 3rd rounder, I really like Kelechi Osemele moving inside to a guard position. Strong as an oxe, big, smart, hard worker, 4 year starter, 36 inch arms. I could see him being able to play both guard positions and filling in at right tackle.