Parts you will need:
Power door panels
Power door harness from both driver/pass side.
Power switches (door lock on driver side, power window switches, power mirror adjuster switch)
Floor harness from a power car (EX, LX)
Power mirrors
Window regulator w/ motor
Door Lock actuator (really, just the motor cause it bolts onto the manual door lock actuator)
Power door lock control unit.
The rods and inner/outer door locks stay the same. No you don't need to rekey. You keep the stock stuff on that. There are a few DIY's out there but they lack a lot of detail. I learned that first hand. Just read and reread them all. It is VERY tedious and time consuming (especially if your doing it yourself). You have to have a weekend and patience if you want to do it right. But in the end it's well worth it. I love it.
I just realized you said sedan. You will have to get everything from a sedan cause coupe/hatch stuff doesn't swap over except for the mirror adjuster switch. The junk yards around here have a few power sedans. so you may wanna take a trip to a junk yard.