They ought to go back to the 1970s slayer. She’s black, lives in New York City in its darkest days, single mother, and kills vampires.
http://buffy.wikia.com/wiki/Nikki_Wood
I new slayer series taking place in a different era would be awesome!
The 70’s slayer would be watchable but we all already know how her story ends (Spike killing her and her son growing up to kill vamps too) so the writers would have to work extra hard to avoid the lull of the audience already knowing the end game. The only way to keep people on the edge of their seats is to constantly put the lives of those she loves in the balance...
Except her son...since we already know he will always survive. Lol