Yea, in order for the SPI engine to use a intake that is made for the zetec engine, you must buy a 60mm throttle body, you an get one from focus central. That allows you to use the bigger size intake tubing.
Even though this isn't a suspension thread but you asked about it, I wouldn't go with drop zone. From what I've heard they suck, heard they don't drop your car down much anyways. Save up your money and get the Eibach Pro-Kit.