i need a Shipping Calculator installed + some other things done

1. i need a Shipping Calculator installed on my ebay clone auction site,seller needs to have box that u enter size and weight so buyer can push a button and get his estimated shipping charges, needs to have usps and ups and fedex, also for manual entry extra shipping amount boxes installed for international shipping, needs totals to automaticly figured on invoice,, something close to what ebay has, i have some calculator programs i dont know if thay are complete or what im looking for so if you bid on this project try and have a backup Calculator program incase mine wont work,, 2. i have 4 or 5 different programs that have different apps for membership, i need for my custermers to fill out one app and have one password and one member id for all programs, mabe linking passwords and member ids together somehow. ,,,tony