OsCommerce modifications

We want to do the following with our oscommerce: 1- Remove the US langauge and keep the Arabic one only 2- Delete all shipping modules and add a new one that is based one the weight. The shipping fees for this new one is determined in the admin panel by stating there how much 1 lb cost, and 2 lb, and 3 lb, up to 550 lb. As a start, we will fill upto 300 only, so make it possible to let some fields empty. If the customer's order weight fall into a number that's empty (not filled with a shipping cost yet), a message that states (Your order cannot be shipped now. We are sorry, try again later) will be shown to him. Also make this shipping module applied only on certian countries I choose later on. The countries are not chosen by default. If a country isn't chosen (which is the default) and a customer wants to checkout shipping to that country, he or she will be given this message (Sorry, we don't ship to your country). Oh yeah, as this shipping module is based on countries as well, make it possible to give each country a different shipping table cost. That's all :)