If you're using a custom provider for managing product information (using the CustomSKUInfoProvider), you will need to use the Product datalist web part or develop a similar web part that will display the products using the custom provider.
You can find more details on the Product datalist web part in Kentico CMS Web Parts and Controls Reference/Web Parts/E-commerce/Product datalist.
Page url: http://devnet.kentico.com/docs/ecommerceguide/index.html?using_the_productdatalist_web_part.htm