I did not install the top one at first and it was not good. Documentation build failed.
I suggest you install the top one, "for Java Developers". Certain Java tools, such as Ant, are required for some parts of the Workbench to work and aren't included in all types of Eclipse (though the support article does say that the JDK, not JRE, is required, so maybe my mistake was not installing the JDK separately).