Some things he may really like there are silly putty (comes in little eggs @ any retail store), kooish balls, squeezy balls, marble mazes are great too and would fit your maze theme, things to look through are also usual hits, kalidiscopes, binoculars, water things too you can buy things with oil and water in them or make your own from pop bottles using oil, glitter, beads in them (secure the tops real tight!).
Many of the above items I use in the regular classroom for helping with attending too. I would suggest you use velcro for your workshop pictures and put on a velro strip then they can move the pictures where they want too. Makes it very flexible. Any other questions let me know. Robin