these roofs, at least the authentic ones, aren't made from plywood and aren't called "pagoda roofs". Pagodas generally have roofs with up-turned hips, it is true, however so do many other Japanese traditional temple structures. The correct name for that roof form is 'sori noki ya-ne'.

Anyhow, they are complex and expensive roofs to build if done in an authentic manner. If something like that is of interest to you, please contact me and we can talk about it. I specialize in that sort of work and could construct one and ship it to you.

Otherwise, there is a fellow down in San Diego - Joe Wood - who does facsimile of various Japanese garden structures using dimensional lumber, and I'm sure he could provide you with something. He can be found on the web.

Good luck!