There really is only one brand but that doesn't mean you can't do the exact same thing with ingredients found at your local home-improvement and arts&crafts supply stores. Just make sure you check for ingredients that aren't body-safe before purchasing.
Cock rings are an absolute must! As is patience. This isn't something you do when you're partying on a Saturday night, it's something you plan for on a lazy Sunday afternoon when you have nothing else to do. Shaving the region is also recommended. A thin layer of vaseline or baby oil will prevent any uncomfortable moments with the molding agent after shaving (just make sure to apply after placing the c-ring around the base).
I would definitely recommend the silicone version over the others (except the chocolate, of course).