Front-end is totally my thing so if you need some tips gimme a shout. As I mentioned you might find it easiest to do actual bitmap drawing straight onto a canvas(a bit of rectangle and text rendering is all you need no?) and if you do this cleverly you can make things able to drag around and such by responding to mouse events.

I'd be more specific but I don't want to bore you and my java is sketchy at the moment... haven't used it in a year or two. ^^;;