Might I suggest a couple of things that helped the tweedles finally sleep through the night.
Every night when I tucked them in I would swaddle them. It was very cocoon like & really settled them in for sleep. I also invested in bed tents - for some reason it helped them sleep through the night.
http://www.amazon.com/Kids-Reactive Attachment Disorder (RAD)-Racer-Bed...=toys-and-games
This is the tent wm had on his bed & worked for a good 2 years.
Good luck - I remember how very exhausted we all were before the tweedles got into a decent sleep pattern.
