"George E. Cawthon" writes:
You should have said the sides would be plywood!
Sleeves would have to be metal at least an inch long which would be a
pita.

Forget the pins and move to a different system if you stay with
plywood.

More generally, what type of wood would you recommend for the sides
that would give good shear strength for the pins at an affordable
price?
I assume that I only would need the hardwood for the hole tearout so
that 3/4" stock would be sufficienct since I could get additional
stiffness by backing up the hardwood with a parallel piece of plywood
side.

I am going to be painting the wood so I just need a wood that takes
paint well. Also, I assume that since I am painting, it still makes
sense to use 1.5" of doubled up plywood for the shelves (with poplar
facing) and for other elements other than the sides holding the pins
and the face frames.