This is probably a little late for you now but I liked "48" by James Herbert. It has a similar style to "The Stand" and is set in post World War II England, where most of the population is dead and a few survive, hiding out in the underground. They too have to battle a dark force to overcome.
James Herbert is an excellent writer, one of the UK's most renouned horror authors and for something a little different but still in the same genre as "The Stand" you could also try "Portent"

Hope these give you some ideas!
tiel