Wow. That sounds pretty stressful for everyone.
I second the recommendation for "No Cry Sleep Solution" for bf-friendly sleep techniques. But the other book I found extremely helpful is "Healthy Sleep Habits, Happy Child" (Weissbluth). It's a great book that talks about what you can expect from your child given neurological development and corresponding natural sleep/wake rhythms. We used both books together when dd and ds were around 4-6 months old, and they've been great sleepers ever since, and no CIO ever. I still refer to them all the time, e.g., most recently when trying to figure out how to ease the transition to 1 nap a day.
One thing that may not be popular, but to consider, is that they are overtired because they're not getting enough sleep (naps included). I found that the more tired dd and ds are, the more of a struggle falling asleep becomes. Of course there is a range, but if you add up the number of hours each baby gets per day, it should be *at least* 12-13 at that age, and probably more than that. I think dd ad ds, for example, got around 14 total at that age -- including two decent naps during the day.
When do they typically fall asleep? When do they wake up in the morning? (I wouldn't "count" nursing in their sleep as time they are awake.) How many naps? When do they occur? How long do they last?
I would also recommend using "No Cry" to eliminate any and all CIO as soon as possible. I think that makes for a couple of very uptight babies, worried about being left alone, missing your company, and mad as hornets about it.
As someone who struggled with sleep issues for the first 6 or so months, I can really relate to what you're going through, and also feel for your babies who sounds miserable about it too! Post back with more info and I'll try to help (re: questions above) some more if I can.