Try the Gallery place at Midmac roundabout or some of the shops up Salwa Road. Also have you tried ID design in the mall on D-ring road?
You can get nice stuff here for a reasonable price, but most of it is made in India and is decorative. Doesn't sound like what you are looking for. For the good decorative stuff people recommend Dariche (souq Waqif) Oriental Carpet Company (C ring Road) Ghassans (behind Oriental Carpet) and Reshi (all malls).