Just before we left Barang Barang seemed to be morphing into something entirely different - lots of Pimp Chic, IIRC.
I always struggled to buy sofas in Singapore - places like Park Mall seemed to be full of either OTT English country or hideous leather recliner type stuff. I ended up with Ikea with the view that it was relatively cheap and disposable, but went for more classic styles (including the ubiquitous Ektorp!). Two of them went to another forum member when we left, one to a charity, and the sofabed came with us and was given away a few months ago, so they didn't do badly
Bed was custom-made made in Jakarta, so I would say unless you want something sleek and modern go to the Indonesian furniture stores. Mattress came with bed; TBH I figured it would last us a year or so 'til we bought a better one but it's still like new, ten years and several moves on.
edit: And a tip for you: measure your lift before choosing your sofa, including the diagonals. We were convinced by the salesman here that ours wouldn't be a problem, despite being hesitant, and the one I chose would not fit in the lift or up the fire escape. Had to go back and I've never been entirely happy with its replacement.
(The men who had to carry those two sold-on Ikea sofas up 14 flights of stairs would probably agree with this tip.)