old houses tend to have poor sound dampening
furthermore, brownstone is also supposed to be poor at sound dampening
if your upstairs neighbor has updated flooring, there may be some sound insulation. Can you hear your neighbor walking around/talking upstairs?
that said, the speakers will be as loud or soft as you want them to be when connected to a receiver. A subwoofer is probably out of the question (unless you keep it turned down, and then it kind of loses its intended purpose since your fronts should be able to output a limited amount of low end anyway)
definitive tech makes some nice speakers. you could buy 3 of those mythos 2's for use as front, center, and left.
The amazon reviewers say it provides ok bass, but with 4.5" drivers don't expect any miracles
i'm not sure if there are any thin speakers with bigger drivers
some threads to look at maybe