Hi Frank
It is not possible to do that with Payment Form. I think you you can add these lists of carpet samples into a Joomla article to allow users to see the list, then at the end of each carpet, add a link to Payment Form (like Order Now...) which allow users to click on to ordeer that carpet
If you want to easy figure out which one they order, I think you will have to create 60 forms in this case (each form for a carpet)
Maybe you should use a shopping cart extension like our Eshop, it would be simpler to setup (although the order process might be a bit more complicated)
Tuan