i think that the tom harrison map is still a pretty solid choice, aside from making your own from caltopo.com and printing it, which may not be much better. the harrison map is really nice in that it’s small, but the extent still includes the entire wilderness and some of the surrounding stuff you can see from the wilderness.
keep in mind, too, that the majority of springs in the SGW are seasonal. only a few can be relied on year-round, and by early september, especially in summers that follow winters of low snowfall, lots of those seasonal springs will be dry. The best way to be sure you’ll have water is to get verification that someone recently saw water at a particular spring. this forum is a pretty good place to ask, and there used to be a water report somewhere, if i recall correctly, but i can’t find it at the moment.