Try this... build a Four-Star 40. I seem to remember someone taking one and clipping the wing, then making a second clipped wing and turnig it into a bipe.

You could learn the low wing characteristics... then advance a little by clipping the wings, then do the bipe conversion.[8D]

CG moves forward when you add the second wing... as the second wing is monted a bit forward. Since I had to stuff my RX battery as far back as it would go to ballance my Four Star as a monoplane, that should not be too big a problem.