What industry is this? I assume sales reps or similar?
Mostly men? Or women?

I would vote for somewhere on the LV Strip. That's the iconic destination, particularly for those that haven't been to LV before.
It depends on budget also. Bellagio / Venetian / Wynn would be VERY expensive, and don't really cater to the 25c player anyway.

I'd suggest checking prices at New York-New York or even at the remodeled Tropicana.
As for shows, check into one of the Cirque du Soleil shows in town.

Though we "hard core" chip collectors like downtown for its history, etc., it feels a bit downscale for rewarding these top performers. You wouldn't want them to be underwhelmed. JMHO.