depends what your budget is matey. I had a mk3 fez with gti engine out escort, had fast road cams, boost valve, 4-2-1 ashley manifold, decat, ashley system back, 2 litre throttle body and maf sensor, powertech air filter was running 160 bhp.

the throttle body bolts straight on if iirc but may need a bit of fetling for the throttle cable mount, tbh it may add a few bhp and make throttle response that bit better but not a whole lot. depending on budget have you thought about bike carbs? throttle bodies? 40's etc? Not as expensive as the turbo route and can get a good amount of power out zetec.

I owned a escort si same bhp engine standard as gti, had a powerflow stainless system, decat, chip, air filter and boost valve, my mates rs2000 couldnt look at it.