Build dynamic html forms using PHP and JS

I need expert in PHP and Javascript for a simple task (~20hr). Create for me a dynamic page that consist of two forms; 1. First form has one selection field that is dynamic (total 4 fields) 2. The second form is dynamic, according to selections in first form (max of 15 fields) Some fields are selections, others are radio-buttons or checkboxes. All the dynamics should be configurable from a config file. All code should be php and some JS. All code should be well documented. I will give specific fields and dynamics requirements to the selected bidder. Please also state your hourly rate, for future tasks.