Immediately: Automatic domain name registration, and automatically creating an addon domain with document root folder

I am currently building an easy to use website building tool. But I have a problem, I need for the person to be able to buy the domain name, where the system will then automatically create an addon domain with the document root folder in Hostgator Cpanel. I want to buy my domain names strictly from NameCheap, so you will have to use NameCheap API. If the domain name is above USD$12.00, I dont want the system to buy it. Let it return an error message. please check it out here [login to view URL] There is currently a system that shows if the domain name is available or not and if it is available they can select it. I want when the person makes a payment that the domain name they selected will be bought and registered automatically and it will create an addon domain name and the Document Root folder for that domain. Also separate from the system, I want a solo domain name buying system where the person can search for domains and get prices and be able to purchase it. If you are not going to respond in 24 hrs don't bid. If you don't understand don't bid. If you are going to charge over 600USD to do this don't bid. If you bid something and then change it don't bid. I am very srs, if you bid with the above mistakes you will be blocked immediately, no joke.