Bathroom shops

If you're looking for the best value for money, I recommend Unigro. Their website is http://www.unigro.be/.

If you're more ecologically minded, however, and don't mind picking up the items yourself, you might like to try your local Freecycle group (freecycle.org). I've seen many items advertised on the Brussels group from sofas to bathroom cabinets. You could also check out the second-hand websites, kapaza.be, 2emain.be, etc.

Good luck!