The folks in Omarama NZ do courses, though if you're going to go that far, I personally would suggest getting the basics first - it would be a pity to be in such an awe inspiring environment, and be focussed on the basics of flying, rather than enjoying the full experience.
There are clubs in aus (gliding club of victoria in benalla) that do intensive courses also.
I don't know about closer to the Uk.