As far as I know, the Su-47 Berkut has an airframe comparable (in size and payload weight capacity) to many light bombers but it still has the maneuverability of a fighter (and actually better maneuverability than most fighters).
It's certainly more than apt to role of strike bomber as well as air superiority fighter - if only there were more than just few prototypes existing.
By the way, have you ever tried to plan your own airplane in X-Plane's Plane Builder? I have. It's not as easy as it might sound like, but I suggest you try, it's great fun (even though thebuilder program has its own stupidities, including absence of undo/redo function...
and some lesser dumbities... but anyway.
You can install the demo version, the only limitation is that the joystick comes unrecognized after 6 minutes of flight, and you have to by lisence to make it work all the time, but the plane builder has no limitations - exept some in-built "features".
Another thing the plane builder is rather useful is that if you have some concept art and would like to model it, it's IMO much easier to make the model in Plane Builder, especially if you have accurate blueprints. There are some limitations, of course, compared to full feature modelling program, but it's good as a beginning - final tuning could be done for example in Blender, since Blender with appropriate plugin reads the X-Plane aircraft models without any problems. And it also exports OBJ files, of course.
