Create & Intregrate payment module Magento / Voice-pay.com

Hi Everyone We need a payment module creating for my magento online store. The module needs to join with my credit card processor - [login to view URL] The people at [login to view URL] have provide some instructions how the module needs to communicate with my magento store - [login to view URL] They have also stated that the current magento / worldpay module is very similar to what we need. So maybe it would be best to simply modify this extentsion. Here is link for this - [login to view URL] Look forward to hearing from you all Regards Jim