Integrate any PHP- Chat in my website with payment functionality

Hi PHP / Webdesign folks I have a website ready and i want to integrate any PHP chat (many free available like PHP free chat etc) in it. It has login and sign-up features already. 99% of the pages are already built in PHP, HTML and CSS. 1. Website in P.H.P already exists, database MySQL exists, minor changes will be acceptable. 2. I just want people in the website to have 1-1 chat with the experts online. Not a chat-room. 3. Also customer has to pay for this chat via credit/debit/Paypal. 4. Online experts needs to be fetched from DB and shown 10 per page with chat now option. Full requirement Document is attached. Lower amount bids will be given preference and you have to make all the requirements work properly for payments.