That depends on a several factors, including number of products you produce and your main goal.
When Amazon-like design will be appropriate? If you're interested in a big flow of potential costumer and you're offering wide variety of products. In this case it can be really useful
When Explanatory site willl be appropriate? If you're ready to costumize your product and when you need to attract people attention. I mean, when each client is valuable to you. Explanatory website helps to focuse each vistitor attention, which helps you to convince a potential buyer that he needs this product.
I would choose the second option, but that's just my opinion.