I like to dabble in the molecular gastronomy stuff too every now and again. I dunno about you IC, but I always come back to the classics and the homestyle stuff, and make sure to do it right. IMO, nothing beats the classics or some good comfort food.
You could substitute either Monterey jack, Fontina, or Provolone. Forgot to mention that I melted some of the cheese in the bechamel as well. Not all of it was sprinkled on top.