OScommerce custom shipping module by weight

Hi, My website is a fashion online store based on Oscommerce V2.2 RC2a. The shipping module required is: 1. Based on weight of items 2. getting rates from Australia Post shipping rates table worldwide. 3. offers EXPRESS POST option within Australia ONLY. - Buyer on my website should be able to see the shipping charges for each item on the product_info page. - Buyer can choose their country on the product info page (which is by default on Australia) & the shipping module will show cost for item to ship to the selected country according to item's weight. - if Buyer chooses Australia: *cust chooses their STATE (There are 6 states in Australia) *after they choose their state, EXPRESS POST option appears with extra cost & the extra cost of EXPRESS POST gets added to the total if customer choose EXPRESS POST. - if Buyer chooses Australia then buyer can see the number of days it will take for delivery using normal post or express post. I'll supply the table for the delivery days for both options. - a total cost of the item + the chosen shipping option (Inc. Tax) should show on the product info page EXAMPLE: [login to view URL] I want to have something similar to above link (the shipping part). - shipping cost is free above $20, I need to be able to enter this amount ($20 or any other amount) of free shipping in the admin section. - if cust buys many items then the same options of normal/experss post with costing appear in shopping cart for whole order NOT per item. - I use PayPal express, whatever add-on or coding you'll make must be ok for PayPal express to understand. Please Msg me if you need any more info. Thanks