There is no generic "bead head nymph". You can add a bead head to any nymph pattern you want. For example, I just ordered a collection of BHNs:
BH prince
BH nymphomaniac
BH pheasant tail
BH hare's ear
If you want a BH prince nymph, you just slide a bead on the hook, and then tie the prince nymph. Same goes for all the other patterns.