Hi, just a quick note, its not a terribly hard install, but the wiring can be a chore, and if you don't have a factory wiring harness for it, I recommend soldering all your connections so you're not removing the wiring to check for shorts.
Anyway, you need:
cruise control servo
cruise control throttle body cable
cruise control engine compartment wiring (from the factory it passes through the firewall where the engine and passenger harnesses meet in a giant electrical connector that can be a pain to work with)
Steering wheel with cruise control switches
Clockspring with cruise control provision (electrical connector next to the airbag connector)
steering column wiring (for the clockspring & steering wheel switches)
cruise control deactivator switch (its a green plunger style switch on the brake pedal assembly)
and if you have a manual, you also need a specific clutch pedal position switch that's red in color, cars without cruise came with a blue colored switch, that doesn't support cruise.
My "SVT EAP" D23E sedan...
done: Recaro's ◆ HID's ◆ BSD ◆ Brisk LGS ◆ SVT brakes & suspension ◆ 22mm RSB
wishlist: built engine ◆ oil sump baffle ◆ mazdaspeed3 tranny ◆ stage 2 turbo ◆ tune