Welcome!
I wanted to first of all ask if you have any sort of regularity in regards to wake time,bed time, or even the time they take their nap?
It is good to start with one thing, and add on as you go.I began using bed routine as the first step in starting(bath at a certain time, and bed to follow etc) and even that one thing made a world of difference. Do you have any of Tracy's books?
Would it be possible to see what a typical day for you and your Lo's looks like?
I wonder if the Sleep Forum would be able to assist with the co-sleeping you mentioned....I haven't had any experience with this as of yet, since LO is just 10 months...but maybe someone reading this has?
HTH