Try Deeside Gliding Club, near Aboyne, in Scotland. Challenging conditions in the wave near the Cairngorn Mountains. Possibly also Black Mountains Gliding Club in Wales. Both these places are airtow only. Clubs that also offer winch launches don't have much work for tuggies, so local guys usually do the tugging. Also, could you cross the Atlantic? very few gliding clubs over there do winching, so there may be opportunity but don't know whether the US welcomes European pilots these days. Get in touch with the Soaring Society of America for answers....
Good luck!