Opencart Manufacturer filter

Project Description:
Please read carefully before bidding on this project:

I require some one to create a filter navigation module for opencart that displays on the manufactuer product listing pages, which will allow my customers to filter the products by category and by price range, the module MUST retain filters if the customer selects to order the products in a different way, changes products per page or clicks to view the next page.

Here is an example of a filter that is nearly what I require but not good enough: http://www.opencart.com/index.php?route=extension/extension/info&extension_id=9885

Developer must have a demo server that you can provide a working demo of your work