Searching around for some scratchbuild foamy planes I found these sites:
Plans may be downloaded for a small donation which would be used to support underprivileged kids and help less fortunate families to learn how to build scratchbuilt rc planes.
Plans may be downloaded for a small fee, you also find some e-book on the subject
Plans may be downloaded for a small fee
Causemann Here you may order complete cutted kits
Technopoint Mannheim from where I got my printed plans as I had no print service around
Don't find what you're looking for, there are certainly more, just use Google to find them.