Choice listings are allowed in some circumstances - basically, if the items are the same and only have minor differences, and there's no variation in price, you can use a choice listing like mentioned, where the buyer has to message you to tell you their preference (this is typically used for items where variation listings aren't available or appropriate, eg name and address labels, where it's the same product / price for everyone, but perhaps different colours, and what is printed for individual customers is different).
Otherwise, those type of listings are not strictly kocher.
If you use a choice listing, you have to be very clear about what the buyer will be purchasing - there's been a few that got into trouble because they showed a photo of all available items and buyers thought they'd get everything pictured. That means you need to show the quantity in the title (eg 1 x Toy), and provide clear instructions in the listing on how to make a choice. Keep the details up to date, as well, removing all images and references to items no longer available.
