Best solution for e-book sales on Joomla site

Dear professional friends,

I've running a Joomla Literature blog for two years. Now I am at the top of Google search list in Turkey, thanks to your valuable shares of components.

I need a simple solution to sell my own books, booklets, shortstories as e-books, namely Downloads over Paypal.

Any suggestions for the best solution? I have found j2store at Portaliz but not sure about its performance.

Thanks in advance friends.