There is a list on trade2win.com although most of the firms there are now gone as it was compiled a few years ago. A couple of well-known, reputable ones (I do not mean safe in terms of your deposit security): - Tower Trading Group - Marex Spectron Protrader. I do not know if they facilitate options trading. Please bear in mind, unless you fulfill the FCA criteria for "elective professional" they will not open an account for you (MIFiD II regulations to blame).