Bob Carlton flies a modified Glasflugel H101 Salto... he put a jet engine on it.

Manfred Radius, another well-known airshow pilot -- and got Bob his start -- also flies a Salto, but as pure glider.

Manfred's website is http://radiusairshows.com/

I think the other major aerobatic single-seat glider is the Swift, but I don't know much about it.

-John