If I had that kind of money to play with, first tackle student housing, then perpetually free tuition, then start seeding some research centres in particular areas of study that fit the school’s priorities. Take a page from Stanford’s Phil dept and just get a Rita of visiting scholars representing -

Rota*

A “who’s who” of modern theology that would make your department a place really want to go because they’d get to meet and take classes from/hear lectures from the world’s best.