Charles, I use a 1 9/16" Forstner bit to cut the holes for my chip displays. The one I use came from MLCS. I don't use mat like you want to use though. I use solid hardwood and frame around that. The bit I use has a sawtooth rim. I run it at a slow speed in my drill press and have never had a problem, even when cutting extremly hard material such as Brazilian Cherry. The item number for the one I use is 9222. I would be happy to loan you my bit to make sure it would work for you. Just let me know if you would like to borrow it. What ever you decide, I agree with Richard, don't buy a hole saw from a place like Home Depot or Lowe's. These tools are designed to be "throw-away" tools and will not last.