Picked up my lumber tonight. We'll see if I did the right calculations to churn 3 of these puppies out - or not. Probably not but should be close. Love the 8' bed in my Silverado. Eight foot lengths should provide all that's needed.
I got 4x4's, 2x4's, 5/4x6 deck boards for the seat, and 1x6's for the back.
As a bonus, I ran into the special forces Brit vet, who served two tours - one in Iraq the other in the Faulklands. He's third generation special forces. Knows a lot about carpentry and works in the lumber dept. there.
I got loading my truck down to a science.....
EDIT: For those interested....the lumber cost was around $300 - so $100 per chair not including fasteners....