Two diferent Products listing in one page

Hi,

If both categories are in the same parent category without other categories in that category, you could configure your menu item to list the products of that main category with the "sub element fitler" setting of the products options tab of the menu item set to "group by category".
Note however, that you'll probably want to increase the number of rows of the listing as to not have pagination as that display mode doesn't work well with the pagination since the pagination is for the products of both categories.