Seems (as of last season at least) Reebok doesnt produce Jerseys for retail store stores that usually carry them (champs, footlocker, that kinda place) thus, the only place to find the jerseys (again, as of last year) is Hawks.com, the NBA store, or the shop in Phillips Arena.
last year we didnt have any big name players on our team, but year before that -- there were plenty of Shareef, and JT jerseys around - i *assume* Reebok reebok realizes hawks fans are deprived now, and will begin to make our jerseys again (i expect Josh Smith, Al Harrington, and Joe Johnson jerseys......)
good luck!