I had the same problems, the OP was clear what he wanted, and I kept missing it.
The main advantage of my design over what I've seen is every time variable can be set, plus I put a decent DC/DC converter that is a real plus. My 1.1d design addresses all the problems I think, including that of balancing the LED currents and brightnesses.
I got some help from Ron H, the second 555 circuit is a monostable that triggers of both edges, which is cool (Ron's design). The 4th 555 was something Wookie found for me a long while back. The transistor switch configuration was purely mine.
