They’ve got the best selection in North America. Lee Valley has some and I think they used to have more because of all the references in the stick making books. But Treeline has them beat. They have a wider selection of sizes of rubber slip-on tips, which means you can probably find a tip to fit your stick rather than shape the stick to fit a limited number of tip sizes Treeline also has two styles of rubber tips, regular and longer. I’m going to try the longer one to see if my grandfather’s cane is useful to me. He was shorter, by far. The cane wood tip is also only 1/2 inch in diameter, and don’t they also stock that size also?
They both also have convertible tips in which a rubber tip covers a steel spike. Treeline again wins this ne, because they have a tip assembly in which the rubber cap simply screws off and on over the steel pike. Lee Valley’s convertible tip appears to have you partially taking apart the assembly to switch back and forth. Awkward.
I’m familiar with this because I have used a commercial hiking staff that converts from rubber to steel spike (street to mountain trail) by simply unscrewing the rubber part.
If you are not in the US, please ask, because I have at least one (old) British stick making book that lists supply sources in the UK. I’ll subscribe to this thread. You might check your libraries for stick making books with lists of suppliers.