Eclipse is a really great editor, which I prefer to use, but the GUI design tools for Eclipse are lacking. On the other hand, NetBeans works really well for GUI design.
Create your GUI with Netbeans. copy a Eclipse .project file (like below) into the project folder change the MyProjectName. Open Eclipse and import the project into your workspace, so you can open the projekt from your Eclipse workspace with Netbeans. Now you able to use Netbeans to create and change the GUI and editing the code with Eclipse.
MyProject
org.eclipse.jdt.core.javabuilder
org.eclipse.jdt.core.javanature