I bought mine from Classic Performance Products (SoCal). Other places sell what looks to be the same brackets. (distributors I guess) CPP sells a frame bracket to hold just a dual chamber M/C without the booster. You could mount almost any mordern M/C to this.
I went with the power set-up on the frame with a remote resevoir. (so I don't have to crawl under the truck and check the M/C with my finger!)
There are some pictures of the unit on my truck on my web (picture) site link.
The "Truck Shop" in Orange Cal. selss the same set-up....but they don't have a decent web site. Compare pictures of the brackets,etc. at different web sites and you'll see they are pretty much identical. "Brothers" truck shop also sells the kits.
VERY worthwhile....I had my 52 on the rack for mufflers & went to 'look and feel' one of the brake lines...it snapped like a pretzel!