Couple seeking a double room for 6+ months

We're a professional couple from Australia, currently in the UK for a year. We're looking for a double room in London, ideally for at least 6 months with the possibility to extend. We're non-smokers, pet lovers (although our pets aren't in the UK), clean, friendly and respectful of housemates' down time. We're looking for a place with friendly and respectful housemates, with a good balance of socialising and allowing each other our space. Although we're not big partiers, we'd love the occasional dinner or pub nights.
Thanks, Jae and Shael