Whatever you do - make sure the rules are clear to all BEFORE the tourney starts...
I bowled in a local tournament group tournament a few years ago. Before the tournament, I was told there was going to be a ball giveaway by some means. I don't quite remember. But that was one of the main reasons I decided to bowl that tournament.
AFTER THE START OF QUALIFYING, actually towards the end of it - we were told that the rules had been changed, and some other means was being used to determine the ball winner. I don't remember the details, but it was patently unfair, and almost guaranteed who would get the ball.
I didn't go back to that organization again.