Promoters requesting we not bring Mp3's. Preference of .wav/FLAC?

Hi Team, got my first big gig coming up and the rig we'll be playing on is a Void system. So naturally, the promoters have requested we not bring Mp3's. We'll also be using CDJ's and I'm a rekordbox user at home.

Have you guys and girls got any preference for .wav over FLAC? I always thought .wav was the way to go but I'm led to believe they aren't able to store tagging information?

Will either format work with this setup? If so I'd probably be leaning more towards FLAC.

EDIT: Thanks for the input everyone. I've opted for AIFF for the safe option and to please the prima donna promoters. They're not doing a great job responding to my messages about what decks specifically we're playing on too. I've concluded the reason they're so antsy about it is because the they've had people rock up with youtube rips in the past.

Typically my library sits at 256 Mp3's so its about time I bumped up that quality anyway. I'll bring my intended set list in AIFF. But leave the remainder of my stuff at 320 in case I have to fill.