Create payment module

Hello, Im searching for someone who can modify my payment gateway module in magento. I had one custom payment gateway module done for my website. But somehow i need a few modifications for it. i would like to duplicate it to be used with the other payment gateway but still using the same API. There is a problem with the API at the moment and i need someone to fix this as well. I believe this is not a complicated job as i've been using this module so it is already been built and it works well but i just need extra modifications and a few corrections. Below i attached the API manual and also the extension.