The issue with stainless is that you need a specific wall thickness and alloy in order to bend it smoothly with no crimping and walls collapsing on you. In addition you will need a mandrel bender to do a tight radius.
It is much better and less expensive to buy them already done.
I have the Harbor Freight bender and it was very useful on bending PIPE for my roll bar but it basically destroyed the stainless tubing that I had.