In a scenario where backups need to be sent from Site B to a repository at Site A and the direct backup cannot complete within the backup window due to connection limitations, a Backup Copy Job is the most suitable type of job. The Backup Copy Job can transfer data efficiently and with reduced impact on the production environment. The components involved would be:

6 (Repository at Site B): Where the initial backups are stored.

4 (WAN Accelerator at Site A): To optimize the data transfer over the WAN.

3 (WAN Accelerator at Site B): To prepare the backup data for transfer.

2 (Repository at Site A): The target repository for the backup copies. This configuration leverages the WAN Accelerators to reduce the amount of data that needs to travel over the WAN, thus allowing the backup copy job to complete within the available window.