For IRAs, the custodian or trustee is normally a bank, savings association, insurance company, or any other entity deemed by the Secretary of the Treasury to be able to carry out the responsibilities. Banks are permitted to use record keepers of their choice. Some banks that act as custodians for self-directed IRAs appoint record keepers and administrators to provide the administrative and ministerial requirements of customers. In all cases, the bank that is shown as the custodian is the legal custodian. The record keepers and administrators act as the agent for the custodian and provide you with the services that the custodian has contracted for.
The custodian, administrators, and record keepers should have a history of providing the kinds of services you are looking for so that you can review their track record. It is important to find out if the staff has specific knowledge about the investments you want to make.