You can use the Datasource to give other data to your Product.
Also a placeholder may contain more than 1 component.
so on the layout on your page item you place 2 components in a placeholder and set the datasource to an item that contain the product data of the specific product.
You can take a look at the Helix documentation helix.sitecore.net/.../index.html
to get an idea how the layout work.
or watch this video www.youtube.com/watch