Sandy, thanks for the info. Yes our suitcases are right at the size-limit and weight-wise well within the 70kg/pp limit. I'm trying to find out if there is any place we can keep them if they don't fit on they overhead rack (and I'm quite sure they wouldn't).
Sudhir, thanks for the tip about space behind the seats in CC, I had also seen those pics while searching on google. But couldn't find any relevant info about the EC cabin. Hopefully, someone here has direct knowledge about the EC cabin in this regard.