Hi,
I don't think Fiat or any other make their own timing belts, I usually fit Gates or continental which seem to be original equipment on most European vehicles. Again they don't fail at any given time, if they fail there is usually a reason, oil contamination, tensioner pulley failure etc. Waiting for a spanner..... sounds like a cop out to me, most toools required are in the average toolbox, if not available at most good motor factors. Good luck with it.
T