The I4 is knocking 150bhp standard and the best 1.8 zetec was only 130?

I know better manifolds etc release a bit of power on any engine but on the I4, removing the EGR should give a bigger equivalent hike in itself.

I can't imagine there'll be masses in it after the mods, but I would go for the I4 if it was a straight choice... chain rather than a belt, more torque and the easy option of fitting the 2.3 bottom end from a galaxy for sod all..