Wedding Theme Suggestions.

You can have old school cocktails like a Boulevardie and Old Fashion. Here are some ideas: https://www.tasteofhome.com/collection/vintage-drinks/.

For masks, you can reserve it for the late hour of dancing, and have your people pass them around for a la hora loca. I do not think guests will want to wear their masks the whole time if they have their makeup done (you, too). If you ask your wedding party to wear a costume, I would strongly suggest paying for their attire as these will not be worn again like regular formal wear. If you will have your serving staff wear costumes, you would pay for that as well. Good luck.