I have a set of the spacer fences,1/4-3/8-1/2, they are very good for making box joints and what they call a combination joint. I didn't drill holes in my table,have always used clamps, but the holes would probably be better.With a little practice they are easy to use and get good box joints. My only suggestion would be to go to Enco or another industrial supplier and purchase some solid carbide spiral end mills. They cut beautifully and cost less than router bits.
Good Luck
Jerry