I don't really think this is a problem for the Zetec's.
Probably should look at getting a chip first if you have an ATX. TB's, V-Cams, UD-pully and all that stuff are nice and add up. However, nothing beats adding a new chip, turbo, cold air intake mods, headers and using a higher grade of gas. If you want all that other stuff you might as well buy a better engine.
Maybe it's just me though?

What do I know, I'm not a car guy, more of a computer grandmaster.