No, I don't think you need to clamp a piece of wood to the kiosk. As you mentioned it will make it a little more difficult to place the hole exactly where you want it. Since you are drilling for buttons I'm assuming the hole size will be 1 1/8 so get your self a good flat wood bit. On the tips of either side of the bit will have a little raised cutting tip that will cut your hole size (as well as the blade along the length of the bit) once the center works itself in. Just take is slow until these tips start to cut your circle into the wood. Once you break through the laminate (you will know becase all you should see is wood and saw dust coming out) then open the drill up to a little higher speed until you break through.