Help with a Form or suggestion.

My company has tasked me with a "virtual tree" for Christmas charity.  Typically we'd list items on ornaments, put them on a tree and an employee would grab an ornament and be responsible to purchase that item.   Essentially I'd like to mimic a "sign up sheet" type format but once an item is chosen by a user, it has to be eliminated as a choice so another user can't choose it as well.  Are there any tools within O365 where this could be possible?