I currently have the vrx 918s. 4 over 4 inside will cover 1500 inside no problem at 110 db back at room. We ran several hardcore bands with it. Derek
Is that 4-over-4 per side, or total? If per side (which is what I would think), then again, the OP doesn't have access to rigging and you can't pole mount more then two boxes. Either way, if 8-15" drivers are not acceptable, I would be hard pressed to think that 8-12" drivers (or worse, 4!) would be agreeable.
Just saying that Tim, who has WORKED the band in question before, stated that SRX/this room combination would probably be unacceptable to him as well. When it comes down to the end of the day, what we "think is best" sometimes falls behind what the promoter wants. (Given technical, physical and budgetary limitations, of course.)