I have +10 years of experience in Python programming.
I am expert in working with different types of API like REST, SOAP, JSON-RPC, ...
I have worked with many APIs like Zuora, PayPal ,Salesforce, Bigcommerce, Google, Yahoo, Yandex, Twitter, ... before. So I think, I will have no problem to implement your Payment Gateway and integrate it with any bank API.
To be able to trust, I have an interesting suggestion for you!
I can make a simple checkout page and integrate it with one of your selected banks api as example without awarding project to me.
If result was OK, then you can trust and award the project to me, and if not you loose nothing and can choose another one.
If you are agree, let's start;)
Thanks, Helmot