What diameter and wall thickness of pipe are you planning on using?
Also, what stainless formula/number?
How much constriction are you looking to accomplish?
I've seen metal-smiths do some amazing things with thin material, bordering between art and voo-doo. Depending on what you want to accomplish and what you are working with it might be possible to do by hand with some homemade dies/tools.
Please post some pictures or drawings of what you are going for.