Hi there, Jenny!
There is a whole forum here dedicated to the South Beach Diet. Just scroll down to Diet Central and click on the South Beach Diet link
The diet I follow (one I mostly made myself based on calorie counting, research, and good ol' common sense) is a lot like the South Beach Diet, so I definitely think South Beach has some ideas worth looking into. I also think 1,200 is too low of a number to start out with, because 1,200 calories is the lowest you should ever go. If you dip below 1,200 calories a day, you can throw your body into starvation mode, which is never good.
I think you should start out around 1,800 calories a day and go from there. You will still be losing weight. Once you hit a plateau, you can gradually go lower.