You're supposed to have 4 sq feet per chicken in the coop....10 in the run. It's okay to go a little under that number (I know I have, at least in the coop) but that's the general idea. Good luck!!!
If 6x16 is the size of your coop, then you can fit about 30 chickens in there, cutting corners. If that's the size of your run, that's only about 10 chickens.
Generally most people go for cornish X rock meat birds, because those are bred to grow very quickly and not eat too much food (HA!!!). They do grow pretty quick (that's what I have) and the suggestion is that for the first week or so to let them have food 24/7, then only let them eat from 7am to 7pm.