For my five gallon batches of cheese, I use my SS canner. The metal is thin enough that I can't use direct heat, so I set it inside another canner that is just a bit wider and put water in it for a double-boiler.
When I make 2 1/2 gallon batches, I use my 12-quart SS pot that is heavier.
I purchased both of these long enough ago that I no longer recall how much I spent on them, but I know they weren't too pricey.