Web"online app" developer

I work for a UK company looking for new web based application developers. We have a test project which details are as follows:

We offer a web based app for accounting. It is very well designed and simple to use. We do not want to copy the design layout but build a site which is similar in it's user friendly interface. The web based app our client want to develop is for producing certificates with client address & information and many test results and details on them.

Please click the link to see an existing SOFTWARE product that is available to do this task.
http://www.cliksoftware.com/pages/niceic.htm?gclid=CMyVrL6U26UCFVAf4Qod2BGCjg
You can download a 14day free trial.

There are many types of certificates but this job only includes implementing ONE as a sample.
Many fields on the certificate form can be automatically filled depending on entries in other fields, saving the user time.

We also need to develop the site for account holders. The account holders will be issued with a subdomain for their account.
The whole site must be secure and scalable so that it can be easily developed further in the future. more certificates added, more features.

If you look around the demo account, you will find many of the features required in this web base app; pages for payment history, contacts & project management & certificate management. A key feature for we want that is missing from FreeAgents contacts page is a search field which brings up matches in realtime as you enter the name. The same could be applied to projects and certificates page.

The design of the app site must be unique for copyright reasons. As will our designs of the initial certificate for this job.

Pages to be included initially will be:

Home/Overview
Contacts
Projects
Certificates
Account Settings

Further developments will include creating a mobile friendly version & iphone app.

Please ask any questions.