That Kia doesn't have "shocks". It has struts, front and rear. They bolt in but you will need spring compressors to swap over the springs and hardware unless you purchase the struts "loaded" with new springs and hardware. Loaded struts cost aprox double what just the strut alone costs.
Examine the rear suspension, especially the shocks/struts.
The 2003 Kia Rio has 52.8 in. of rear shoulder room.
The 2003 Kia Sedona has 39.2 in. of rear head room.
The 2003 Kia Optima has 36.2 in. of rear leg room.
The 2003 Kia Optima has 54.4 in. of rear hip room.
The 2003 Kia Sedona has 37.2 in. of rear leg room.
The 2003 Kia Rio has 53.5 in. of rear hip room.
The 2003 Kia Sorento has 39.5 in. of rear head room.
The 2003 Kia Optima has 37.6 in. of rear head room.
The 2003 Kia Sedona has 65.1 in. of rear hip room.
The 2003 Kia Sedona has 63.1 in. of rear shoulder room.