FTP you would have to do either using port forwarding, or by using smbmount to 'mount' a share from the various internal servers to ibays on your SME.
SSH you can do with port forwarding pretty easily - 2221->host1, port 22; 2222->host 2, port 22
Neither ftp nor ssh will let you re-direct to different internal hosts based on the hostname the remote user specified (as far as I know).