I created a post about a week ago about having 2 under 2 and what tandem/side by side that people would recommend and got some good advice.
http://www.nappyvalleynet.com/double-bu ... 16010.html
I too thought that P&T would be the only answer until many said about mountain buggy duet. I had a go of one in Peppermint on Saturday and is really lightweight and it is the same width as a P&T (obviously only the wheel part of the p&t) but still, it gets through doors just the same. Think I'm going to buy one plus the freerider scooter that can be used as a buggy board for my son when he gets a little older (19 months now).
I am not going to buy the pram part as 2nd time round, I know that although lovely, it is a waste of money particularly as this buggy lies flat. All I would say is it didn't look particularly comfortable so would defo need a sheepskin liner or something, never thought of a cocoon. Maybe need to try that out before I buy one.
Good luck, I'm due in March.