How can I download JavaFX Scene Builder 2.0 ?

I found the instruction https://docs.oracle.com/javase/8/scene-builder-2/installation-guide/jfxsb-installation\_2\_0.htm But I dont see any JavaFX Scene Builder in the Additional Resources section on the listed page .

I have to call a external java file on a click of button in javafx application.

Should I learn Swing or JavaFX? Which one would be a good choice?