Add shipping features to our checkout page

Need to add shipping features to our checkout page. Right now we only have a flat rate option price that we input from our admin page, with API real-time shipping quotes for Fed-Ex, DHL, UPS and USPS. located on the checkout page. take a look. [login to view URL] Now this is what we need.... 1. Ability to calculate the least cost shipping from USPS and place that as the default Shipping Rate. 2. Ability on our admin page to up-charge all shipping prices by any amount designated. On all carriers listed on our site. 3. Ability for all carriers once a customer selects the shipping method to have a printable automatic label to add to the Box when the order is ready to ship. 4. Ability for all carriers to send the customer and us as well the tracking number automatically once a customer makes and order. 5. Ability to notify the carrier that a shipment is waiting for them to come pick up on an order is placed an flagged as in process. 6. Should Integrate with our Admin Panel on the back end connecting with our order section of the admin panel showing tracking number and shipping method as well for reference. !!!Attention!!!!! Bidders i give this project to another coder, he says i can do but after getting award he says i am unable to do, so please read description carefully before u place bid.. this site is fully modified using OpenCart , so only bid if u have OpenCart knowledge If u cant do then dont place bid and waste my time...... i need this to be done in time and i mean it!! Thanks