Well, personally, I'd build a whole new cabinet, because a pet hate of mine is combo's and heads with the the controls on the top at the back. WHY do they do that!!!!!?? On top at the front I could understand, but prefer them on the front where I can see them from pretty much any angle. In fact I'd build it as a head, then you can build a few diff cabs with different speakers and be even more mad scientist!