how to start developing plugins with *Ultimate*?

Hey guys,

I'm trying to get started developing a plugin using Ultimate IDEA (I am not keen on cloning community edition with GIT). According to the documentation it is possible. I downloaded Ultimate, however I unable to add "IntelliJ IDEA SDK". The only SDK I can add is "JSDK". However JSDK does not like it when I point to IDEA installation folder. What am I doing wrong?

Thanks
Szczepan