Swiftwill.com is a great company for maximum security. They go to great lengths for security.
At times that can be inconvenient or even outright annoying, but that's the price you pay for
ultimate security. Chilihost and Phatservers are also good. The latter are two all around good
hosts with knowledgeable staff, so they'll have good security, but nothing too unusual.
Swiftwill has some unique security systems.