182399 XML integration w/E-Junkie

This should be a fairly easy project for a coder knowledgeable in PHP and XML. I need a simple script written that allows us to integrate [login to view URL]'s payment system with our production/fulfillment house. Our fulfillment house can accept info via XML and info on that can be found here: [login to view URL] Info on 3rd party integration with e-junkie can be found here: [login to view URL] End Product / Deliverable: The end result we're looking for is to be able to use e-junkie's product links as the purchase links on our sales page. When the visitor clicks the link or the add-to-cart button, that product gets added to the cart. Then, the customer will go through e-junkie's payment system like normal (with whatever payment processor we've setup...that should all be seamless since it's handled on e-junkie's end). Once the order goes through, the relevant details of the order should be sent to Kunaki for them to fulfill the order. According to e-junkie, the can send the order details to a script on our server (see details at e-junkie's link listed above and note #2 below). This should be written in PHP and of course security is vitally important. Notes: (1) Since e-junkie provides a field for item number and kunaki requires an item number, assume that we'll be inputting that item number into e-junkie as we add new products. This number will be whatever number has been assigned by kunaki. That way, that piece of information can be easily passed through to kunaki's system. E-junkie already integrates with SwiftCD out-of-the-box using this same method...they might be a good site to look at to see how they're integrated. (2) According to e-junkie's site in the link above: "E-junkie will send all the order data using POST to your URL only for successful completed payments. Currently, if E-junkie server is unable to reach your server, it will not retry." Since this is the case, I'd like a way to log any potentially failed transactions if possible. I'm open to ideas or other solutions for this piece if that's not possible. (3) Since kunaki can send back an XML response with the shipping costs, I'd like to be able to use that info during the customer's checkout, but I'm not sure if that can be integrated with the way e-junkie works. Please advise on whether or not this is possible.