In that pic the very front pair and the smaller bushings you can see there 4 larger ones landed up in the second row and the rest are the corasponding peace's that go underneeth.
If you get an extended cab kit you get 4 small ones like I did or you can just use the smalls for the back and normals for the front. I couldn't open the link you posted, but these are what I have and they are pretty cheap.
You can always just use delrin pucks or shaved down hockey pucks, anything will work lol