Looking For Extra Large Room

I am fiftyish year old (young :-)) female who is looking for extra large double room (max £650)for me & possibly later for another member of my family who would move in too (together we would be 2 persons ( both adults). I'm interested in to rent in area of SW London, Kingston, Surbiton, New Malden, Richmond, Putney, but I'm happy to move to other area of Greater London (Rickmansworth, Amersham etc) if there is suitable nice room. I'd prefer unfurnished room or partly furnished as I have my own bed and it would be great if there is some extra storage space. Please contact me if you could help to rent suitable room. Thank you in advance :-)! Marika