Create an online tax questionnaire

Looking for a website designer/programmer to convert a tax questionnaire currently in excel format into an online form. The website/form will contain many questions which the end user will be required to answer in various ways for example, tick boxes, radio buttons, drop down menus, selection boxes and text fields. The form will need to change dynamically depending on answers given to specific questions, for example, if specific question is answered in the positive then an additional question/table is added. There will also be various numeric questions which require calculations for example a series of questions with numeric answers which are added up to show a total of all answers added together. Some sections of the form will require the end user to be able to upload supporting documents in PDF or JPG format which are stored on the backend for viewing or printing. As the form will be quite lengthy and require a number of hours to complete, the user must have the option to save the form during completion and resume at a later date. This will be achieved by a username and password to allow the user to login and out of their form during completion. As the form will contain sensitive data, the site (front and backend) should be encrypted. A backend system to allow site administrator to login and view all accounts/forms (complete and incomplete) and view/print any uploaded files (as mentioned above).