The first are typical beadhead hares ear. The colors (can't judge size) could represent a number of nymphs, including the March Brown, the Hendrickson, and a general attractor nymph. The second pic, focusing on the light colored wet flies, suggests a light caddis, as their is no tailing.
If you are looking for something you already have to imitate the sulfur nymph, go with the classic pheasant tail. I think sulfur nymphs are basically a light brown to dark brown. When they break the shuck, but still have it attached to their backside, they will present the dual coloration exhibited in the "Half-and-half" or some of the other patterns mentioned that incorporate blonde elements in the thorax region.