Sheesh! This is where our drummer comes in very handy. I've never seen anyone better at advancing gigs with sound/light companies. He sends them a full stage plot and input list with every single thing needed onstage (except guitar stands...for some reason he always forgets them), and he has a whole list of questions he asks, including if they have enough staff to run the stuff. You've really got to contact the companies themselves and ask that kind of stuff of them. Sometimes it happens anyway, but if it does, you'll know that the sound company are liars and can't be trusted.