I wouldn't have thought any reasonable standard hotel in West London would be intolerant of someone staying at the hotel receiving a visitor to their room. If it has a card system to use the lift or get past the ground floor you can meet the girl in the lobby or bar and take her up.
As to finding a girl, put any of Olympia, Earls Court, Kensington, West Kensington, Hammersmith into the search box here, or on AW, and you will get an idea of what's available and what's good. Note also from Olympia you can be in central London in 20 minutes, so no need to limit yourself to local girls.