I'm lowerered but debating the extending. Lowering will keep you on the ground and you'll lose the wheelie, unlesss you really really want to wheelie, because you will have a lower center of gravity. Extending the wheel or stretching the frame will create a larger turn radius for the busa. The longer you stretch it the harder its going be to turn. Harder but not impossible, oh and it'll also cause you to slow down more in the turns.
Now if you drop it and stretch it you have to consider the fact that you be dragging parts and your turn radius is also going to be affected by the lean angle you lose when you lower the bike.
hope this helped!