Alien Bee is popular because it was ultra-cheap and was marketed to students. The huge drawback is/was the very dim modeling light (you want at least 250 watts of quartz light in a lamp head, not a 150 watt household bulb). AB's wimpy modeling light by itself explained why most professionals quickly graduated to bettter-designs. Also, AB's flash output info is deceptive..they say to ignore watt-seconds but you really should start your thinking with that number before you buy into AB's claims.
Norman is/was popular (especially in high volume studios) because it's incredibly rugged physically and built to more beefy electrical standards.
Take a look at
Strobist for cheap/flexible/portable alternative approaches (eg with Vivitar 285V strobes).