One other thought - you don't want the desk to be too thick. For the best ergonomics, you want the vertical distance between your hands and your thighs - i.e. the thickness of the keyboard, plus the desk, plus a small gap - to be quite small. Image search for "desk ergonomics" for diagrams. Related to that, pay attention to the height of the desk from the ground. You want your feet to be flat on the ground.
