Product template page to list accessories

We have product pages, and list of accessories. all in two different categories. We have a custom template for the product page – but each product has a different set of accessories that need listed.

My first thought would be to create a custom field, and listing each accessory page ID. And then getting that added to the template page.

Is this the way to go? Are there any other directions that make more sense to go?

Many thanks in advance.