I am looking for,a script which can do following things. I am working on ebook free store category based sorting searching etc. do you know any
Do you mean want to start eBook store? If yes then there is lots of free and paid scripts. You can use osCommerce or Joomla for this.
Joomla with virtuemart is also a good choice. you can set the good as downloadable and set the price 0 , then the user gets a downloadlink after checking out the cart