I used a solid core door for mine actually. It was about $30 at a local lumber yard. I just mounted it on top of a simple bench that is built out of 2x4's. I put the whole thing on wheels so I could move it in and out of my garage easily. It's nothing fancy, but it makes a nice big work surface that is also nice and flat.

Kinda messy right now. One of these days I will probably build some shelves underneath so I can keep things a little more organized.

Russ.