Lisa at the Thai place on Toynbee Street (not what I'd call pretty) has a truly magnificent pair on her for an Asian bird (very heavy and a delight to play with).
Shirley at Sante on Whitcomb Street has a larger than average if not slightly pendulous pair on her. Both demand more than the going rate to get them out and played with.
As for 'East London', you're going to have to invest shoe leather like the rest of us mate. This stuff doesn't just fall into your lap on demand you know, make some effort.