write prestashop delivery plugin

Dear all, For our RESTful JSON API we need someone with experience with the eCommerce platform "PrestaShop" to write a simple plugin or module. It would need to do the following:
 1. Upon checkout, query our API with at minumum the dimensions of the product, the weight, and two postcodes (point A and point B) to create and return an Estimate. The Estimate object returned contains an ID, the cost, the distance the package will travel, the pickup time (defaults to current time), a delivery window (between 1-2 hours after the pickup time), an expiry date and time for the estimate (10 minutes after creation) and the other information provided to start with.
 2. Display a countdown timer during checkout until the estimate expiry time. If the Estimate expires, the user must check out again (delivery times could change etc)
 3. When checkout is complete, call the API with the Estimate and tell it to create a Delivery with provided properties.
Obviously any errors would need to be appropriately handled.

 Regards, Team