I looked around Epsom with a Hong Kong Chinese family. We liked it, Co Ed, lovely buildings and grounds and a solid if not the most stellar academic reputation. It has a tradition of serving the families of medical professionals so a particular strength in preparing pupils for medicine. We didn't see too many Chinese pupils so I don't know if there are many but in any case it is how well they integrate pupils from other cultures rather than the sheer numbers. CLC, where friend's DD ended up, is the Boarding school that has best implemented strategies the make sure the pupils mix and that has large numbers of overseas pupils including Hong Kong Chinese Perhaps you could ask the schools if you could speak to a Chinese pupil there?
It is a mix of day weekly and full boarding at Epsom but the full boarders that we spoke to had busy weekends and were often invited out to friend's houses.
The only thing, I don't know how long it has been coed but it felt like a boy,s school with girls, that could be a drawback or a good thing depending how you look at it.