I'vw had good luck on E-bay by just typing in "Isuzu" and search "all catagories".
I know for a fact that there are a number of Isuzu wheel sets on there right now. You just need to look at every photo and description to find the right style and size. Some sellers don't know what wheels go to what flavor Isuzu. Check your owner's manual for specs on wheel size,because two were used.
Keep on 'truckin.......John