OP, what do other pilots at your club fly? I would want to have a similar performance glider to friends with whom I might fly cross country, and advice from owners of the same type can be helpful. Who will maintain it, and what gliders is he most familiar with?

Potential resale is obviously important to you. In the UK Schleicher, LS and Schempp Hirth gliders are probably the safest investment. I was surprised at the idea that an ASW 27 would be difficult to sell. I think the opposite.