Setting up a customised gift box from existing products?

I sell bath products and have a number of different categories with varying products, eg bath bombs, soap, shampoo.

I would like to set up a gift box selection where customers can pick say 2 bath bombs, a soap and a shampoo, from the products that I sell.

My existing gift sets already have attributes set so that customers can choose from a list of different gift wrappings with a dropdown box, so I'm familiar with how to do that.

However, as you can imagine I sell a lot of different products which change on a regular basis, so it seems a bit labour intensive to create the gift box this way, is there another way I can do it? Specifically if there is a way that the products can be linked so that if someone puts say greasy shampoo in their gift box that it alters the stock level on the main product?

Thanks!