Tank,
By One design, you mean that PW-5 thing? Yes, one design gliding was the best idea to get ruined in execution for a long time!!
I got the idea that it would be better to form a class around these-
http://www.aeros.com.ua/structure/al/index_en.php
Cheap, easily transported, obviously not a huge performer but the idea is to have every one the same. What do you think?