I got mine from Kustom werks. I got them before the whole thing with the custom arms became an issue. it only took about 2 1/2 weeks to get mine. As for what thickness for the bottom plate 3/16" and 1/4 inch on top.
I guess i will never get mine, been waiting almost 5 months on them. Getting ready to make a trip to TN to pay eric a visit. He said they were ready a month ago.