These are the 2 clamps I used.
The pegboard frame I made from a 2’x4′ sheet of pegboard with 2×2’s framing on the back. I used the better grade of lumber from HomeDepot for the 2×2’s so it is quite flat. Here are a couple more photos of the pegboard frame. One showing how the back of it looks. It was a little bit of a pain bolting the clamps underneath, but using wingnuts helps a lot. I also use a clamp across the top of the part to tighten it between the clamps. The 1st clamp has a feature that is supposed to allow you to tighten it further on top, but it did not work well for me.