[gb2world]

You might be able to manually build such a page by using the advanced search on extra fields and using the page URL generated by the search. But if you have a lot of categories and extra fields to search, it could take a while.

As a alternative (not exactly what you asked but close), you could look at the quick search by xcart.mods. It can do a search based on the extra fields - which seems to correlate with how you are managing the sizes in your store (?). You could also speak with xcart mods if you use something else besides the extra fields (for example options or variants). Last time I asked, they were considering adding that capability.