its 1" thick to get the caliper spaced out from the mounting flange, not because they wanted a thick bracket. then they milled it down 1/2" to accommodate a thinner bolt.
so...a 1/2" thick bracket, with 1/2" "washers" to space it out from the flange, would get the job done and do the same thing.
If it was half inch thick, I would recommend steel as the material. Are the front brackets steel? It was my plan to use steel regardless.
