FFS, you lot struggle to read don't you.........
Yes, they are easy to convert. Last one I did was just a matter of trimming the bolt, running a die down it and buying a recessed nut. Some brakes have a larger shoulder that may make this impractical.
Not sure about buying a new shaft, unless it's a very expensive brake. Anything under 105 sort of price, it'd probably be cheaper to buy a new brake!