Hi and welcome
I honestly don't know the answer to your question as I have no experience of Chinese engines, or for that matter RS250s, but I think a lot of Chinese engines are based around Suzuki GN series engines or Honda engines like the XR series. I suppose you have had a look at the Projects section of this website to see some of the amazing engine swaps people have done, might give you some encouragement or insight. Hope you get sorted.
Ian