Jon, The snubbers are not required when building a diode bridge. However, what I have read on here is that the snubbers help eliminate some of the diode switching noise.
I actually built two sets of diode bridges from the schematics above. One without the snubbers installed and the other with the snubbers attached. This way I can easily compare/contrast the diode bridges.
I haven't really decided which one I like better, since they both sound pretty good, plus they were built last night.
Perhaps you should do the same and experiment, so your ears can decide what arrangement sounds better to you.
I hope that this suggestion helps you with your project.
Sincerely,
Andy