Company formation website required

We are looking for an e-commerce website with a backend XML interface to enable the online registration of UK limited companies to the UK companies house register. Data is caputured online along with the payment details. This data is then transmitted to the host website and the transaction completed. Online Document will need to be incorporated to gather this information. We will need error reporting, and the site can be tested before going live. We have extensive information as to the correct formatting for the interface, and several potential clone sites to use as a template if required. We need the ability to update the site, and if possible allow a plug and play/content managment area to add information to the website. Good homepage, very corporate in design (white background) is essential. No flash please. Domains already purchased. Delivery within 1 week please.