Matthias
You can do this with a database (CMS) table. Set up a table that has all the attributes that you allow the user to select (ie: skin type a, skin type b and place the URL for the product that matches those attributes in the table, maybe have recommended product A, B, and C.) When you match the user input against the items in the table you will get a the URLs for the product that best matches - display this and allow the user to select it and go to the store to purchase.
Mike Custode