Cancel and Hold unverified Paypal Orders in Magento

We have a magento online shop and want to cancel all orders, which has been made with an unverified paypal account. Unverified accounts can be created, when the bank account has not been verified by paypal user. So paypal user buys a product with unverified paypal account and cancel payment after having received the product. No chance to receive money again for seller. That's why we need to have a filter in this process. The process is like this. Customer buys a product in our shop and will be redirected from magento to paypal. After payment, paypal will send information to magento via paypal api. If paypal send information about unverified account, the user will not see magento success page (important), but another unsuccess content page, with information about canceled order. No order confirmation will be send. Oder will be canceled automatically by extension. Restrictions: - This small extension should be work for multiple stores, so unsuccess content page can be modified for each store view. - We need the possibility to assign different product categories and sub categories, where this extension should be active. For unsigned product categories, standard magento payment process should be used.