To give a few more details:
We glued two 14"x14" pieces of MDF together. This was so we could mount the wood to the drill base and then mount the jig to the wood. There was not a good way to mount the jig directly to the base with out drilling holes into metal. Also, mounting the jig to the wood allows you to reposition the jig easier if you don't get it aligned correctly the first time.
Before screwing down the jig to the base, we determined the height the base needed to be. We did this by setting the jig in place (as close as possible), inserting a ball in the jig and our largest drill bit in the chuck. We figured the drill bit needed to be 0.5" above the ball to easily get the drill bit in and out (We tested). This left us with 3.5" to drill holes with (which is more than plenty).
Hope that helps.