CARTASI XPAY MODULE FOR PRESTASHOP

Hello to all, i want to improve on my shopping cart Prestashop 1.4 a payments gateway by CartaSI called XPAY. I have all documentations and i have already the module installed on my OsCommerce working. Payment term : When job is done and I accept the final project : 50% When I receive source files, and the installation will be successfull on my page : 50% For each payment PAYPAL will be used. Looking Fw to hearing from You