Since the original Nivomats are too expensive, which chassis do you recommend?

Just because of the Nivomaten original-sachs-HA-damper had a treat. Since I don’t see a normal and easy-to-use solution here, I think of a complete racer, but preferably the same height as original. I am a. out of the age b. no woman that I want it deep & hard! I prefer a wolf in sheep’s fur. So just stay looking. Since I once had feathers in an Audi Lowtec, and the bucket is well located with it, but still was not hard, I thought of such a thing. A complete chassis is already available from 570.-. What do you think about it? KW drives in with 1300.-, but I never heard anything good about them. lg Batbike