Everything I needed was in-store at Lowes. I used a PVC sprinkler riser. The steel spacer insert does the heavy lifting, so I'm not sure how necessary the PVC riser is but it does seem to add some extra stability. The wedge spacers I used were composite construction shims that I had laying around from some other home improvement project. The shims only gave the bracket a little bit of angle. I've seen others use metal wedges which may have had a steeper angle, but not sure where those were sourced from. The spare I'm running is 285/75/16. Tire only makes contact with front and rear support bars, does not touch the crossmember.