For Sanitary - Look at Chawri Bazaar, Kotla & Ashok Vihar Market .
For Wooden Furniture - Look at Kirti Nagar . There is a very good Furniture market in South Delhi . Most People r unaware of it . U get very good new & second hand furniture at bargain pricing . It is just next to the Gurudwara in Kailash Colony . Do have a look .