the 3d mesh has to have the texture linked/or saved with it.
When you save the mesh the texture is also saved with it or at lest
the area that is covered so that you can do a change of textue in pepakura.
the site is one for icons. you can try this site http://www.warbirds.jp/kiyochan/index.html for go from Japanese to English just click on the right side under wre you put the web address. The left buttion is for English to Japanese.