Magento features update

We need some updates to Magento 1.4.0.1: 1) PO Number field for Orders - Customers can enter an optional PO number if they want to during checkout - Set Prefix code for each customer (3-chars) followed by '-' ( i.e. customer Party4Ever's prefix is P4E- ) then their PO number P4E-12345 2) Fix Fedex Shipping calculator - We will provide item weight, dims - Fix FEDEX carrier shipping quotes to include dimensions and get correct live quotes from Fedex(test and make sure works for international countries) -If multiple items, each will be calculated separately and will sum all item shipping quotes If you have any samples or have done anything similar please provide any links. We require seeing features working on your system and payment will be completed once files and install info is provided and we are able to install successfully on our system.