JWM with Sparkylinux is very good. But you will have to install several codecs-fonts-apps etc ... this .iso file is not preloaded or not out of the box iso.
I have seen, recently while searching the web, the JWM Configuration Master in Puppy and requested our Supermoderator-Pavroo made a .deb out of it and he said it will soon be ready.
So JWM is awesome and only problems are
1. Taskbar customization
2. Menu customizaion
I guess both the above problems will be fixed with JWM Configuration Manager
and, for not being out of the box problem you need install everything on your own.