The low friction belts are stronger and don't stretch out as easily as the white ones, due to the material. As for what you need with the sway bars - you will want to keep the plastic pieces from the kit (sprue B, I think) which I no longer have and am trying to find a replacement for
Then you'd want to get aluminum mounts to replace the plastic ones that come with the kit (2x #53916), the sway bar kit (#53844) and the sway bar stoppers (#53827) to keep them from moving left and right in the holders. You don't HAVE to replace the mounts, but I did.