The J201 is quite unusual and it is still manufactured but in SMD model (not thuhole), some folks use a sot23 to thuhole adapter that works fine with some extra work.
Righ now I have checked mouser and they have J201 in stock (smd and thruhole models): www.mouser.co.uk/All-Manufacturers/_/N-0...1+transistor&FS=True
However, if you are using for a different model, maybe the closest jfet you can get is the 2N5457, 2N5458 or MPF102.
You may need to adjust some resistors using this procedure:
Im not aware of suppliers for jfets in Brazil, maybe asking in audio forums you can get some ideas. However finding alternative parts and adjusting them to your circuit is fan and can lead you to new sounds