Worldpay

We are a building services company that have recently signed up with World Pay to take debit and credit card transactions.

We currently post invoices to domestic customers following completion of work and they either pay by cheque, bank transfer or call to give debit/credit card details.

I am looking for a World Pay plugin that will enable our customers to enter their invoice number/value and make payment. It would also need a facility to add a percentage on for credit card transactions.

The only plugins I can find relate to purchasing goods though an online site.

Can any point me in the right direction.

Thanks

Gary