flat, room for double - London

We are a couple, husband and wife without children and young people opened by experience of living with just one woman or couple in a home or flet, preferably a studio in the area 1,2,3 a maximum of four in London. Do not smoke, do not drink, do not have children or animais.Por order came just work. I'm not willing to pay well over £ 350 per month (with bills included) water, electricity, gas, internet. Do not look for luxury and rather quiet, with a good atmosphere. So having some of the genre please contact. Thank you. Arley