Look at the US distributor websites and see what the current offers are.
For some, like Linhof and Sinar, you may need to contact the representative and ask if they have any educational discount programs, since they're not widely advertised. For instance, a representative may let instructors of photography at universities know about a discount that's available to their programs or their students, but they might not keep their website up to date, and they might not spend money to advertise such discounts in magazines. I know that Bob Salomon has announced the availability of educational discounts for Linhof occasionally on the LF forum, for instance, but I don't think I've ever seen them advertised elsewhere. Sinar is also a very hands-on kind of company that might be more likely to sell equipment directly to a studio through a representative on a regular sales and service call than through a dealer, and educational sales are likely to work the same way, through personal contacts.