I don't want to register my products twice ...

Hello, We were recently using Lynk's shopping cart/ordering
functionality and must now switch to a new provider. What I liked
about Lynk was that the only parameters we had to pass it when adding
to cart were the name of the item, the price, a source url, and a store
id. What was nice was that when we added a product to our site, we did
not also have to add that product to Lynk's site. Does anyone know of
a comparable provider of such shopping cart/ordering functionality that
does not require us to register all our for-sale products on their site
and allow a similar API to what I reference above?

Thanks for the advice, - Dave