What brand/kind of diaphrams(mouth calls) do you use for bugling and which ones for cow calling. Where can I buy them? What kind of success have you had with them?

I use the Primos Ivory and Imperial Palate mouth calls most for both bull and cow calls. I think they sound good with practice and if required a bit of back trimming. Should be able to buy them at most sporting shops or online from Primos, Cabela's, etc. For bugling you should pick up a tube as well. I personally use a Primos Terminator with mouth calls only b/c I had one prior. Various others that would do the trick, that are just tubes and would cost less than a reed type such as the terminator. (BTWwith the terminatorI remove the reed portion and just use the tube to amplify the sound of my mouth calls. So if you already have a reed bugle/tube just remove the mouth piece).