Swing gui for community project

Hi,

I want to start a community project hosted on GitHub. I am developing in IDEA and have some small GUI classes. I want to keep these classes as open and compatible as possible to give developers a chance to drop into also with other IDEs. What do you recommend to design the GUI classes? Of course I would like to use the GUI designer if possible?

Should I avoid the GUI designer?
Should I put the source code into the class?
Should I use the GUI designer with standard Swing components only?
Are you aware of other tips and tricks how to setup such community projects?

Thanks
Thomas