Love the setup on both; there is incentive to continue to at least play them even if you think you have qualified, otherwise the single play tourneys are going to be a total shock to the system. Anyway, my guesses:
Oakmont: 68
St. Andrews: 64
Agreed there are a ton of great players, but I think a lot of them have already posted rounds in the low 60's in both qualifiers. Even with unlimited play, staying consistent over 18 holes at Oakmont is so tough. I had a 29 on the front 9 and then blew up on the back. Good luck to everyone!