Opencart One Page Checkout Professional

Here is the latest One Page Checkout module for opencart.
Demo :
Frontend : http://marketplace.x10.bz/ocart/index.php
Backend : http://marketplace.x10.bz/ocart/admin/index.php user : demo Pass : demo
Link : http://adf.ly/8TIUh

Hello I'm looking for a refined controlled One Step Checkout, Not One Page, can you please allow me access to a fully functional demo somehow, seemly I can't test on your site "You don\t have permission!" is the message I keep getting in the admin. I'm looking at other solutions, your seems to have promise, however I would like to test it front and back before buying. Thanks.