The task of becoming a payment service provider, conceptually, involves two basic steps: finding an acquiring bank to partner with and finding a payment gateway software product to use. People often confuse these two steps or order, in which they should be taken. If you want to obtain a merchant account yourself and/or provide merchant services for others, you should keep in mind that payment gateway partnership concerns, primarily, the technical aspect debit and credit card processing. An acquiring bank is an organization, that will underwrite you, process transactions on your behalf (and on behalf of your sub-merchants), and assume financial liability for your operations (face chargeback risks etc). That is why selection of an acquiring partner is the task, which comes before payment gateway selection.
If you need more information about acquiring bank partnerships, you can find it in our article on Paylosophy.