I can't help with the design wall you are asking about, but I made a "portable" one out of insulation board from somewhere like Home Depot that might interest you. I covered it with Warm and Natural and duck taped it on. Mine is 48 inches wide by 70 inches tall. I cut about two feet off of the top when I got it, but I sort of wish I had left that part on...in hindsight.
But this works fine for me. When I am not using it...which is rare, as it turns out... it can hide behind my door, sort of. I am going to take a picture, but I am too lazy to move the bags off of my doorknob, so it won't look like it hides too well in the picture.
Just info for you to think about, in case it might work for you. It didn't cost too much, fabric sticks well to it, and I can even pin a whole quilt top (okay, sometimes it sticks off) on if I want. I am really happy with my design wall. Normally it just leans agains my closet doors, but I can move it easily if I want in the closet.
Okay, off to take pictures. I have a small but cozy sewing room, so ignore all the extra stuff in the pictures.
Dina