Custom E-commerce process programming(repost)

This is a programming requirement for an ordering and checkout process that has three possible routes for the customer. The module is to accept orders for prescription medicine products - there are three possible routes (one: private prescriptions paid for online, two: health service prescriptions, paid at a flat rate online, three: health service prescriptions at no charge). The customer first identifies if they are 1, 2 or 3 (and if 3, will be asked to select the 'free' category into which they fall - e.g, child, pensioner etc, all categories specified by the government to receive free prescriptions); then selects the product, and is taken to the relevant checkout (i.e, either pay the private price, the health service flat rate, or receive the product free). This module will look and feel like the main shopping site to which it will be attached, and will ideally have a 'My Account' linked to the main shop, with reporting features for sales, deliveries, etc. When prescription shopping is completed, the shopper is taken back to the general store. This is NOT a straightforward shopping cart which can use an off-the-shelf solution. ## Deliverables See the flowchart document attached for a step by step guide to the prescription process. The module should be closely related to the general store, so that the customer does not feel he is leaving one site in order to buy his prescriptions. However, Magento does not have the functionality for the prescription process to be built into the general [login to view URL] PLEASE THAT I AM NOT ASKING FOR YOU TO GIVE ME AN ECOMMERCE SITE, THIS IS A SEPARATE PROGRAMMING MODULE TO BE ADDED TO A SHOP.