Wood will will handle the amount of heat in pressing just fine. Heat is not a problem, unless you plan to leave your iron face laying on it! :D
I have a fairly large "multipurpose" table for which serves as a large pressing board. I made the pressing top out of an inexpensive, 1/4" melamine sheet (board). I covered it with one layer of Cotton batting (Warm & White) and Cotton canvas. I did NOT wash the canvas first. I pulled it tight as possible, stapled to the back with hubby's staple gun, and then misted it well with water bottle. As it dried, it shrunk slightly making a very tight, very hard press board. This is the same method that Sharon Schamber suggests for press boards except that I like the melamine-coated material for this purpose, it is hard and the melamine doesn't soak up any excess water.
The silver material is not necessary and too much batting makes it easy to distort blocks when pressing. Cotton canvas and a Hard Surface is the way best to go IMO.
Pictures of my press board top:
http://www.flickr.com/photos/athomesewing/3969491448/