Do you want your students to connect with books? Street lit does just that; it provides a mirror to the students and shows their own reality.
I don't have much in my collection because most that I have seen is really more appropriate for high school and beyond. I do have the Bluford High series and that has been quite popular. By the way, Townsend Press sells the books for $1 each (plus shipping). Very reasonably priced. They are kind of an odd size, but put them on display and they are gone.
The New York Times has an excellent article on street lit and its popularity. I find it fascinating that this sort of thing makes it into the NYT.
The one concern in all of this expressed by some is that street lit takes away from other African-American literature. I don't see it. At least in my experience, the two types of literature are read by different types of students and, interestingly, students who read the Bluford High books are willing to cross over.