Let us not forget about Jane Sharp, who is a foremost specialist in the Russian avant-garde (among other things, she wrote an important book on Goncharova and Larionov); Rutgers has a very good terminal MA program. And if you would want to delve deeper into Eastern/Central Europe and their respective avant-gardes, Steven Mansbach at University of Maryland is the right person. I believe they also offer a free-standing MA degree.