Actually it was much simpler, I just used a hole saw and then cut the board in half...so you get 2 rails from one board... does that make sense???
I had to use my little drum sander to clean-up the holes (i did this before cutting the board in half)
I used a 1.5" inch hole for the front (i think) and a 3.5" for the back (I sure of this one since I had to buy a new hole saw for ~$16)
-jj