Do I understand you right that you want me to switch from synapse to SimpleSFTP.pas?
FYI. SimpleSFTP.pas uses synapse. So it's not a matter of switching.
It's just that SimpleSFTP is a working version of a SFTP client.
BTW. You can't use TFTPSend to do SFTP. In no way !!!
Or do you want FTPS.
Because FTPS is very different from SFTP.
FTPS uses SSL (TLS) for a secure FTP connection. You can use TFTPSend for that (in the way you are trying).
But SFTP is FTP over a SSH connection. Very very different and you can't just do it with TFTPSend (you'll also need libssh2 library).
So which is it you want? FTPS of SFTP?