Hi Bongo STI.
Yes Peter (the owner) is very experienced and has a wealth of knowledge with regards to pinto zetec and anything Ford. He also knows his cars. He is responsible for the set-up of my kit car, which I'm very pleased with and a lot of the kit /specialist /rally car guy's use him.
I would research what you want him to do first, when discuss your expectations with him in depth before you decide to use him.
I seem to recall having read threads, on this site, about guys who's car didn't go quite as well as they expected, after Sanspeed worked on them.
But I for one will use him again on the kit car.
Hope that helps.