They are B. R. Creations, Dark Garden, Axfords, and Voller's. For leather corsets, I would recommend Paul C. Leather. B.R. Creations is run by Ruth Johnson. She is very dedicated to corsetry and makes what I feel are some of the best corsets on American soil. Her corsets are meant for daily wear are very durable.
Materials are satin, heavy cotton, and leather.
She also produces a corsetry newsletter that comes out four times yearly. They tend to be much showier than the B.R. corsets and are often favored by those who wear their corsets only a few times a year, or are interested in historical re-creation. Recently they have begun to produce leather corsets as well. Axfords and Voller's are old British corset companies which produce a variety of corset designs. Mostly they are satin, but they also produce corsets in PVC and leather.