asterisk users - Mar 2005 - Stable CVS or Head CVS for using TE110P ?

Hi,

I'd like to know which version of Asterisk performs best and most stable 
with TE110P.

I don't need any other features (it'll just terminate interasterisk
calls
without any other feature - so there is no need for CVS Head features or 
? ).

Any info on setting up secure interasterisk IAX connections (only one way) ? 
With IAX authentication by certificates ?

Thanks in advance,

regards,

Rob.