How to allow "Bank Transfers"
Unless William has addressed your "Bank Transfer" question, and you actually mean you want users to pay by entering their bank details, often known as ACH transfer.

You will need a merchant that allows that, an example post on this: https://civicrm.org/blogs/adixon/iats-next-generation-payment-processor-acheft 

The link William provided indicate IATS and Vanco offer ACH,