The items that fit your Honda Stepwgn (RK) are shown below.

The fourth generation "RK" Honda Stepwgn was only available in Japan, but has become a popular import to other right hand drive countries. As with previous generations, it comes with a standard double DIN sized radio, so no new double DIN fascia is required. 

Be careful when removing the original radio fascia, they are fragile and are easily destroyed during removal.