seicento sporting mpi suffering intermitent power steering failure along with speedo and rev coutner failure, I have changed the speed sensor and power steering ECU has anyone got any other suggestions?

The EPS needs the speedo so if the speedo readings are playing up and the EPS goes at the same time, its either electrical or gearbox related.
As the rev counter is also playing up I'd head for the dash earths and give them a damn good 'remove, abrade, clean, refit, tighten' session

Cheers

D