Need a suggestion on Paypal API for my Codeigniter Project

I am creating an website, using Codeigniter Framework, related to e-commerce that supports multiple sellers to sell their products on my site. By taking the following structure in consideration please suggest me an appropriate Paypal API:

A seller 'X' will first register on our website, then he will create his product that he wants to sell. The Buyer will buy the product posted by the seller 'X', he will pay using paypal in my a/c. that is a paypal merchant account and the purchase will be saved in my database and will be put on hold until I approve it as a successful transaction. Then using cron job a page with appropriate script will check the payments pending to the sellers (who are selling their products on my site) and pay to the seller 'X' automatically by cutting a small percent of the service fees through my paypal merchant account.

Keeping the above in mind please suggest me an appropriate API for Paypal like Adaptive Accounts, Adaptive payments, Paypal Pro, Payflow, etc. as I am totally confused on which one to use to perform all the above actions perfectly.