need a joomla developper for component customization

hello I have a real estate website i wanna sell construction plans on it. i have a component for joomla call ea estate agent who offord me a listing of properties. i want a listing of the construction plans that i can afford with many categories and attributes like the listing of this component [login to view URL] and i wanna add the fonctionality of paiment with only paypal plugin. The client goes on the site he views the listing of differents construction plans. he will choose one of them buy it on paypal and after he will be logged in the frontend area where he will give some information (either by writing in a text input or by adding files to his frontend area) so that we can treat his purchase when we have all the documents required and after he will wait when we finish we will send him and email and tell him that he can log in frontend and download his finished plan of construction. Yours Sincerely wicem