CS-Cart shipping plug-in

We need a shipping module or plug-in for CS-Cart to determine shipping costs on multiple-item orders. For example, an item that ships for $10 alone should not ship for $40 if a customer wants four. Similarly, the $10 shipping cost would still be 10 bucks if a second item, a small packet, let's say, is ordered at the same time. But if the small packet were ordered alone, it might be $3 (or whatever) to ship. Some of this functionality may already be present in the CS-Cart system. We'd like to have a dynamically changing block that shows a subtotal of all items ordered and a notice that free shipping will apply if X dollars more are spent (depending on the customer's location). There are a few other requirements. Some items may be very irregular in shape or weight, and for those we'd need the script to notify a customer that his shipping can only be quoted by telephone. There are more than 20,000 items in our catalogue and we upload the data with CSV files. As a part of this project, we need clear instructions on entering the required fields to make the plug-in work as it should. As yet we have not added package sizes or weights to the data base, but we are prepared to do this upon instructions of the programmer to run the plug-in effectively. Finally, if there are icons or other graphics that will help to make the shipping features clearer to the customer (such as a truck!), these should be provided in the installation, which is also expected.