Standard shipping Module for Virtuemart Modification

Hello, i need someone to modify the Standard shipping Module of Virtuemart for me. I need an optional choice of Insurance added in a following way: each carrier will set a % of the total order and a min. insurance value (2 new colums in the database table). When a customer will get to the shipping page during checkout, he/she can choose a particular shipping method. Under each shipping method will be a checkbox with optional shipping insurance calculated based on the order total so that if a customer checks the insurance box, the value will be added to the total order along with the shipping value. If the shipping rate has tax applicable, the same tax will aplly on the insurance. I hope this is clear. If not, please contact me for clarifications. Thank you.