Intake manifold, and Bigger cams from Crower or Cat. I love Comp stuff, but those are too mild for what you want, and they need to be split duration and lift (depending on how the head was ported, the Zetec really favors more on the intake side). Especially in the lift area to avoid clearencing the head. Don't be afraid, it just involves very little grinding.
Oh yea, big MAF & 30lb injectors (good for up to 200whp [SVT fOCUS has 'em that size]), plus a custom chip