How to get Amazon Seller Central orders programmatically?

We have been manually been keying Amazon orders into our system and would like to automate it. However, I can't seem to figure out how to go about it. Their documentation is barely there.

There is:

• Amazon Inventory Management (AIM) API: That is supposed to manage orders and inventory
• Event Notification Service (ENS) API: Get order notifications
• Seller Central SOAP API: Upload inventory and manage orders
• Amazon Marketplace Web Service (Amazon MWS): Manage inventory and orders

So hich do I use? Using REST instead of SOAP is very much preferred. Can anyone point me out some better documentation/examples?

I think Amazon's API is a confusing mess to deal with. I just wrote a simple tool to extract data from my Amazon wishlist and it was far harder than it should have been.

I would guess that you want to use the Marketplace service, but I could be wrong. If you're dealing with PHP, there is a PHP API that you might find helpful - Tarzan (link disabled - this package is apparently no longer available)

Here is a Amazon forum for that should help: http://www.amazonsellercommunity.com/forums/forum.jspa?forumID=32, and a PDF overview