If you don't fancy building the engine yourself use Ian Howell at Fiesta Frenzy as all the other tuners ring him for advice on the zetec anyway.

Steel rods, forged pistons, proper inlet manifold, bit of head work and plenty of boost should see 350bhp

I would personally go for a GT28RS with a .64 T3 exhaust housing

Speak to Grant at AET turbo's, he's your man for turbo's

Same sort of money but alot better spool up and drivability.