Custom form creation with math equations

I need a reliable programmer to create a custom form with math equations. The form will include products name, their prices, optional attributes, customer data, custom discount(both in dollars and percentage) and tax. It is almost like a shopping cart but without payment gateway. I have created that using wordpress plugin, but it is quite slow. I need to run this off of the browser due to mobility. I also need a system where all this information can be stored. Following is the demo link: [login to view URL] I am looking for a reliable person, who is proficient in JS and php, and capable of fast turn around. There is potential for more work. Skills required: Javascript, php