best lie flat buggies?

Hi,  

I have read that you can get a lie flat buggy where the seat also converts into a carry cot style seat.  Would anyone have any ideas about this and what it is? I have trawled the web for this but cant find anything.  This is my third and, after having a Quinny for the first two, would like something that isn't cumbersome and heavy. 

Any suggestions would be greatly appreciated!!

Thank you

Sarah