The entirety of Samurai Pizza Cats is available on DVD from Dicotek under their Easter Star label.
http://www.rightstuf.com/rssite/acti...ItemName=es054
And if you're interested in the original show, Kyatto-Ninden Teyandee (Legendary Ninja Cats), they have that too.
http://www.rightstuf.com/rssite/acti...ItemName=es048