Virtuemart Joomla Tradeline Paypal

I need a virtumart extension made theat is compatible with joomla and can accept automatic payments through paypal. I need an extension that can give users 500 dollars in credit that they can use to purchase items. I want the credit to only pay for 70% of the product and the rest to be paid by user upfront.. at the end of each month i need the customers to have an option to pay the minimum payment 10% of the total balance. for example: a customer buys a shirt for 100 dollars, the customer pays 30 dollars up front and the credit takes care fo the other 70 dollars at the end of the month the user has to pay either 7 dollar minimum or the whole amount (would like the 10% minimum adjustable). Please skype me [login to view URL] or email me