[Jon Stratis]

Basically, what you're looking for is something that works exactly like a fishing rod does - it flexes when pulled, many can even completely double over before breaking. Yet at the same time it provides sufficient spring to snap up straight when the force is released. The key is finding a rod with the proper strength to be straight with your hook, yet flexible enough to bend over backwards.

I would suggest your search for material starts there, in an industry that has pretty much already perfected what you're trying to do.