WinSCP is an open source freeware SFTP client for Windows using SSH. Legacy SCP protocol is also supported. Its main function is safe copying of files between a local and a remote computer.
Though EditPlus does now support SFTP file transfer natively, it sometimes fails to connect to certain types of SFTP servers (see fix). You can configure WinSCP to use EditPlus as an external editor. Make sure you have WinSCP version 3.7.2 or higher in order for it to work properly with EditPlus. You can download WinSCP here.