Rate of fire isn't an issue. Rate is set by the audio file, and the one I'm using was built by stacking single shots atop each other. Just have to pack them tighter. I'll have to try a higher rate, though, to be sure the flashes just don't blend into a constant beam. Might need a slight change in resistors.
Making it loud enough? Don't have any idea, other than a big amp and a ruggedized speaker. That is going to be difficult, and is going to take some heavy-duty power.
Ron Wanttaja