First of all, do you want to work for the British or the Chinese? If your English is not good, I recommend you to go to London. There are huge Chinatowns and Chinese factories. It is easier to find a job, but renting a house to eat Transportation is more expensive.
If you speak good English, go to Birmingham and Manchester, because the cost of living in these two cities is definitely lower than London. But Manchester's Chinatown is still bigger than Birmingham's, making it easier to find work. And the afternoon tea in Manchester is 50% off, haha.
London is of course the best city and a real big city. But because it is so big, public security is not good. But it is easy to rent an apartment in these three cities, but you have to look at the area. Some areas have poor public security. It will definitely be much better if you live in the city center or a white area.
Of course London has the largest Chinese population, Chinatown is the largest, and there are also a large number of Vietnamese and Acha.
In addition, the current economic crisis makes it difficult to find a job, so think twice.