Tein is suppose to be a good company. I have seen their products and they were beautiful. Tein is big in Japan, but I don't know if they are any better than Europearn products. Just by looking at them, they look very high quality. (i know i'm not explaining anything. sorry)
Anyways, the spring rates on B14 Super Street coilover will be 336lbs/in front, 280lbs/in rear. It looks pretty good to me. Not too stiff or too soft. I would really like to try this set on my car when they come out.
I don't know about the distributor, but go to www.tein.com and you can e-mail and ask them.