Design a search Website

Hello, I´m creating a business of redirection shooping to Brazil. My client will purchase things on the american purchasing site´s and I will redirecting this goods to Brazil, delivering on cliente´s house in Brazil. For this, my client need make the search by my site and, after they choice the product, comparing prices, they will buy the product. After the purchase, the purchasing site(ebay, amazon) will sent the goods to my addres in US and I will sent this product to Brazil. But, before my client buy this good, I will give to them all informations about tax, transport, time to delivery and etc. In conclusion, I need one search site of products in other´s purchasing site´s, actualizing my client about the total cost before buy this goods. My site need read the price of the other site´s.