System requirements to implement or Allows customers to make payment using Credit Cards

Hi Team,

Here we have below queries Kindly Suggest.

1.System requirements to implement or Allows customers to make payment using Credit Cards, Debit cards or Online Banking?

2.We want to know Technical & Functional Dependencies to implement above online payment services to external customers?

3.Do we require any External Components to Interface with Bank Payment processing?

4.Before we implement Biller Direct, is it mandatory to implement SAP BCM or any other Banking Interfaces we should develop?

Kindly Suggest!!!

Regards

Sudhakar