Wordpress Related Posts

I have a wordpress blog based on dog food that contains a series of posts (custom post type 'product'). Many of these products are exactly the same except from their size: E.g. Dog Food Product 2kg Dog Food Product 10kg Dog Food Product 15kg Another Dog Food Product 2kg Another Dog Food Product 10kg Another Dog Food Product 15kg I need a way of linking these products together so that the other size combinations are stated in the post content. If viewing the post 'Dog Food Product 2kg' there would a section in the post body saying "Also available in: 10kg | 15kg". These would link to the appropriate posts. Products that should be linked together have the exact same post title except from the last work (which designates the size). I don't have a problem with an existing plugin being customised to work as I need.