Why look for ready made, more of a niche market and therefore relatively more expensive.
Get some simple HSS square stock from someone like Ashley Iles and make your own.
Important thing is to maintain the thickness so that you have the rigidity, sometimes round stock can be an advantage, using the natural curve to give the side clearance.
Ashley Iles are often at the bigger shows with trays of HSS blank stock to select from, Yandles is not a million miles from you.