For FX & Eclipse, it depends on your version. For Mars, I had to set it as an FX project and it was more tricky.
For Neon + Java 1.8, IIRC, it's more out of the box. I don't believe I had to do anything more than the normal gradle setup. I also HIGHLY recommend you install SceneBuilder and integrate it (in eclipse, you just have to add it's path).
With that said, JavaFX is a shift from Abelie Forms to fxml. As a group, we may want to discuss project setup and if we want to enforce a more MVC approach? SInce you can have Swing components in a JavaFX frame and JavaFX components in a Swing frame, we can attack it two ways. My thought was to attack the main frame/menu first, and include the map and other frames into the JavaFX frame, pulling them in one at a time if needed, tackling the map last. The caveat is you will be running on two main threads, one for JavaFX and one for Swing. So it has to be managed.
Personally, to get a feel for JavaFX, I tackled TokenTool first. You can see my progress so far in the latest build. It's in git hub but I don't include it in my builds yet, so I currently have TokenTool and TokenToolFX. (TokenToolFX was a clone of TokenTool for easy reference so I haven't removed the bulk of the old classes yet, and in fact, that project can run both versions.) I'm sort of excited to try some of the new effects and add expose them to the user (blur's, shading, etc). Again, total WIP. I eventually plan to integrate it more with MapTool as well, so it packages with MT, can run as it's own app, but can also launch from "edit token" to create/edit said token. So it needs access to the maptool project...https://github.com/JamzTheMan/maptool/tree/126.96.36.199