You definitely want to get "several." We picked up six of the little buggers, and they're quite social. They get upset when placed in isolation - when cleaning the brooder or checking vents for pasty-butt. The first one into the "jail" and the last one out will scream for his/her siblings. (We have since cut slots into the cardboard partition we use to separate them - they can see each other from either side, and they're much more calm about being moved from one side to another.)
That said, "pasty butt" is a big deal, and can kill your chicks in less than a day. We had it, and two of our chicks were severely constipated. They were very loud, and continued being loud even after we released the torrent of chickie-poo. I expect there was discomfort from being plugged-up.
I can't say I'm an expert, but if the chicks are being loud, it's likely that something is wrong.