It would be very useful.
I don't know of any site that does that - i go to pistolforum.com, lightfighter, m4carbine for a good idea of what's out there. Some of the big names do private classes as well if you contact them directly. I know Greg Ellifritz does classes on his own and for TDI, Robert Vogel does classes, as does Steve Fisher. Mad Duck Training is another good source.
Really, it depends on what you're after - tactical disneyland, shooting skills, medical, mindset/psychology of aggressors, etc..
Nice people fall to the manipulator. The manipulator crumbles under the assertive. The assertive shrinks before the aggressive. The aggressive have no plan for the assaultive. The assaultive are unprepared for the homicidal.