Create new contact form and PHP database in a website

Bed and breakfast website that we are revising for s client. Your part in this would be to change the existing form's script and create a database so that when the form is submitted, as well as the above, the enquirer's contact details are stored in a MySQL database for subsequent use by client, e.g. Sending newsletters, Christmas cards, special offers etc.

There preferably needs to be a Captcha on the form, and there needs to be an Admin or back office section to enable the clientto add/modify/delete records, and to enable them to display or print or export to a spreadsheet part or all of the database, the ability to print address labels might also be a required option. There is no requirement for ASP scripting, PHP would be acceptable.
We are a small firm (2 of us) of web designers in Shropshire.