Jen, as you know, my AB's arrived yesterday and I'm LOVING them!
You will get a sync cord with every flash head you order. So I now have 3 cords. I never thought about this until today, but if I want, I can now use one of these sync cords if I want to move my speedlight off camera. Kewl! You only need to use one sync cord, as the flash that is plugged into your camera will trip the other lights.
If you're ordering, you'll need:
the flash heads and a stand for each, although you may already have good stands. I up'ed the anti and got the heavy-duty, air cushioned ones and they sure are sturdy! Each flash head comes with a 15-foot power cord and a 15-foot sync cord;
modifers - grids, barndoors, umbrellas and/or softbox. I got all of them(Christmas came early for me!)
if you want wireless triggering - a transmitter and receiver.
That's it! Easy peazy!
I have a question about high key stuff. Is your background supposed to be so bright that the blinkies go wild, or should it just be at the upper limit without going over the limit?