The Norbertines Fathers of St. Michael's Abbey are excellent, I would recommend the order to anyone in a heartbeat. They use the OF (with kneeling for Holy Communion) at the abbey, but many priests from the abbey do celebrate the EF. They run a boarding prep school and several parishes, but do not work in higher education.
I personally know one Norbertine and he is the most orthodox, reverent, and knowledgeable priest I know. He always celebrates the OF, but he would "collect" the kneelers of the church (not the abbey) to make a communion rail. And one time he celebrated an OF Mass in Latin. He mentioned several times things that were lost such as churches (and priests) facing East and Sacred Chant.
I don't know much about the Mercedarians, but I heard that they are very orthodox and use the EF.
Two very orthodox orders that work in higher education are the Dominicans and the Institute of the Incarnate Word (IVE). The IVE run many seminaries around the world. The Norbertines, Dominicans, and the IVE are having many vocations to their orders. You should also check out the Congregation of the Holy Cross (they work exclusively in education. I heard the many of them are orthodox but also many aren't -- one of their members invited Obama to Notre Dame) and the Marians of the Immaculate Conception.
Good luck with your vocation!