I found it easier to do "Save As" from Terminal, and name it for the system you want to log into, then edit the .term file (its a standard xml preferences file) and look for <key>ExecutionString</key> and following it is usually a <string></string> - simply insert "exec ssh -Y remote_host_name -l remote_user_name so it looks like this:

<key>Execution String</key>
<string>exec ssh -Y mymachine.com -l iamgeorge</string>

When you double click this .term file it will launch Terminal and log into the remote machine automatically.

(By the way, the -Y option forwards X11 packets to the Mac Desktop if you have X11 running on the mac, it can display X windows from the remote system (you may have to set and export DISPLAY=:0.0 in the .profile hidden file in your home directory)