Any suggestions for light (i.e. umbrella fold) double buggies?

[boundarybabe]

We live in a flat and are going to TTC number 2 - hopefully we'll be in a house this time next year but I'm preparing for the possibility that we won't be. I have to carry a buggy up and down one flight of stairs.... so any suggestions?

Am looking for a double that will fit a 2-3 year old and a newborn.

I had a Mclaren Twin Techno. It was really light, folded up small and had my 2 yo and newborn in it.

Not that expensive either compared to others which helped!