Any of the Hatori "140" pipes from the last few years will work well. The older 693, or better the 698 or the latest 699 pipe will be ideal.

Note though that the 699 pipe requires a special header - I do not know if one is available for the Saitos. The 698 is just as good and could be fitted to the standard Saito header via the teflon coupler that comes with the pipe.

James