I've got a Robinsons / Requisite XFull grackle noseband. It isn't the best quality but it was either that or pay a fortune for one, which I didn't want to do.
I have a horse who is somewhere between a full and Xfull so I struggle with bridles too. I'm currently hunting for a reasonably priced (ie I won't pay £150 for a Barnsby cavesson bridle and then £50 for a drop noseband from them to match on top...) bridle with drop noseband but I don't see why I should have to buy a cavesson that I will never use. I did speak to Heritage about having one custom made but they weren't keen to do it.