I'm thinking way back but remember an article on building such a tanker. I'm thinking maybe in lou kroarc (sp) book. I'll see if I can find the article and scan it. Basically you wil find the parts you need in a plastruct catalog look for the tube,tank ends and tube rings, IIRC you will find valve assemblies, and handles also. A trailer kit of your choice will supply the suspension to fit your needs.