coustomizing magento extinson

Hello, This project is for a very experience Magento coder only. we have the Magento extension ( [login to view URL]) And would like to add a bit more options on it . At the moment its using the Amazon API & soap to get all the stock levels from the Amazon web site But it can update only for basic inventory , If for exampled we would like to copy a dress and this dress got a few colours and sizes then the extension wont be a beal to copy all of this to the magento shop . What we want is that the extension will be able to download items with multipal colour and size and have the exact stock on them and also automatic create the correct attribute set just like the magento configurable items.