Amazon Ordering Tool/Script/API - Places orders through Amazon for specified product/seller combinations.

I receive Paypal payments for multiple products I sell. Currently, I manually match the orders with the product on Amazon, find the seller I'd like to buy from and place the order. Placing the order includes selecting the product or products, selecting the seller, specify quantity, enter shipping info, choose payment method, confirm my credit card number, choosing shipping terms, confirming the order and finally placing the order. I go through the entire Amazon POS (Point of Sale) terminal for every single order, it is very time consuming. I need a way that I can somewhat automate the process. I am open to ideas and all ways of design. When you bid, please send me a message on how you would go about accomplishing this. Preference will be given to those who have worked with the Paypal APIs, eBay APIs and are familiar with Amazon.