Since the question was posted under "Personal Protection and Self Defense," the original poster might be interested in some of the more modern schools. I would consider many of the police and military training systems to fall under the heading of martial arts-- after all, that's what "martial arts" originally meant. Thus the Marine Corps Martial Arts Program, the army combatives systems, etc., would all qualify.
I suspect that a search of "combative shooting" on google would turn up several other systems that teach modern firearms combatives.
David Sims
"Cuius testiculos habes, habeas cardia et cerebellum." - Terry Pratchet
My opinion is, in all likelihood, worth exactly what you are paying for it.