Payment Gateway for Joomla (J2Store)

I have a website using Joomla and an online store using J2Store. I have a payment provider linked to my bank account and now I need to create a payment gateway. The provider needs to use openssl for signature creation, I am currently trying to figure out if this is on the fly and openssl needs to be installed on the server or if a one off geeration is all that is needed. Phase I: I would like a payment gateway that works in Joomla and with J2Store, with an Administrator console to manage parameters like Terminal ID and Merchant ID, various target URLs such as payment successful and payment failed... Phase II: I would like this payment gateway to be flexible to work with other shopping carts in Joomla, so that I am not tied to one in particular. Phase III: I would like to have a switchable payment gateway so that I am not reliable on my bank, but can, if required, just select a standard gateway such as paypal or others via an admin console in Joomla. Basically, first get it to work, second decrease dependency on ecommerce plug ins, third, decrease dependency on payment gateways. Phase II and III are dependent on the success of the site, but I am anticipating success. Please get in touch if you can do this kind of work and for an on line chat or [Removed for encouraging offsite communication which is against our Terms and Conditions -Section 13:Communication With Other Users] session for more details