As far as power goes, they work fine with receiver power. From what I've read, they don't dip below 6 ohms at any point so are not a difficult load. But with the 87db sensitivity, more power is better if you want to get really loud.
I've also run them with a 250 wpc amp, and they were fine then too. With room size, I'm not sure about that, but I suspect it wouldn't be a problem, they are a bookshelf after all.