I've got the Dummies Guide to PCOS which is good. With PCOS it does seem to be all about diet and exercise. Anything else seems to be a maybe it will, maybe it won't! I've heard low GI is supposed to be good, not sure about low carb. As long as you're eating the right ones and not overloading on them I'd say you'll be fine.
The trouble I had with SW is that in theory you can eat as much pasta, potatoes, rice as you want on the extra easy plan - and I would even though deep down I know that I don't lose weight if I do that!! I've switched to Rosemary Conley now, it's about portion control so whereas I'd not bother weighing pasta or potatoes before I have to now and I have a lot less of those as a result. I feel much better now after a meal, satisfied rather than stuffed!
I suppose I could have switched to the original plan at SW but at my class all the consultant talked about was the extra easy plan, I was just a bit disheartened and decided to try something else. Perhaps you could give that plan a go if you've found a good SW class?