welcome to the site. I have a 1999 sephia modified a bit. mostly engine upgrades. there are a few suspension upgrades. I have for suspension strut bar, intrax lowering springs dropped 1.75" front and rear.
There are also coilovers availiable.
for my engine upgrades I have 4-2-1 header, lightened crank pully, cold air intake, 2.25" exhaust cat back.
Brakes I upgraded since the stock unit sucked I ended up getting drilled/slotted rotors and ebc redstuff pads.
body I only have a front bumper started on my body kit
there are tons of things out their for kias now
the best place to start looking is
www.kfxperformance.com
oh and most engine upgrades sephia/specrta have the same motor. suspension is a bit different and brakes are a little different! hope this helps.