To clear up some confusion on the name:
The Barcelona Chair, daybed and stool were designed by Ludwig Mies van der Rohe way back in the 1920s for a giant party called the International Exposition in Barcelona, Spain. That's how the chair got its name.
There was never a real sofa, however. Just the chair, bed and stool. The couch was merely a design inspired by the original piece, emulating the style, but elongating the dimension.
So there is no such thing as a "Barcelona Couch Reproduction," really, but since there was no such thing as a Barcelona Couch in the first place, there's no such thing as an authentic one, either.
There is, however, the Barcelona Daybed, which is merely a twin-size mattress made of leather with an attached pillow, which is sometimes called the Barcelona Sofa or Couch. Check out a Barcelona Daybed Replica if that's what you're after.
Well, now that that's all out of the way, let's get shopping!