Thanks for the suggestions. I started looking some more yesterday and
saw a lot of the closets only go half way down instead of all the way
to the floor. So I will modify that aspect--saves on wood.

I thought there was a problem of screwing into the edge of plywood ie
the top shelf going into the top edge of the said panels--hence the
corner block. I am going to use the steel poles.

I am still worreid about the sides being rigid enough, even if I only
go half way down. I now the pole will add some sturdiness to the sides.
Maybe I'll just and a small L-bracket near the bottom of the side
panels.

I'll have to visit the idea of just hanging them from the wall like you
suggested.

Thanks again for your input.