Keavon Milton tested at the Combine at 6-4.0 and 280 pounds, not 6-8. So not really the length of most NFL OT's.
If they need a tackle off the practice squad, the lead candidate has to be Blaine Clausell. He's 6-6 329, typical size of a tackle, and was on the Labor Day practice squad -- he has the most experience in the Pats system. Picking up another college TE and hoping he can pick up the Pats offensive line system in a couple days is pretty risky. In fact, I think he's one of three guys who have been with the practice squad the entire season (Asante Cleveland, Darius Fleming the others). That must count for something.