There are no perfect matches as written.
You can play the Zhodani light or dark. The written material supports both. Dark Zhodani can be easily cast as "Yellow Menace" stereotypes from old movies, but neither light nor dark is very Chinese.
The Vilani are, after ten thousand years in space and significant cultural pollution from Earth, all over the map. So are most Solomani (aka Terrans, *us*). The Solomani Confed keeps wanting to be a fascist state but hasn't quite succeeded with the masses.
The Imperium as a whole is incredibly diverse. While genetically dominated by the Vilani and Solomani, there are also significant groups of other human variants with their own cultures, including four that have had notable empires of their own: the Geonee, Darmine, Luriani, and Suerrat. By 1105 there are Vargr just about everywhere, local human and alien races, and, of course, the Solomani roots are *us* and are hardly homogenous. Stir for seven hundred years, then collapse and let simmer for 1700 more, and finally turn on the lights, remix for a thousand years, and voila, the published setting.
You can imagine, if you really need to, that the Imperium is the current and former British Empire circa 1800. Every place (world) you visit is different, but there are elements that carry over: language first and foremost. There are local languages, but Galanglic is everywhere. Some worlds are very "Imperial" and others barely acknowledge the Imperium in their day to day lives. The Imperium is a nation of "Men, not Laws" even when the worlds themselves have laws. Individual nobles range from vital to useless, and their allegiances include the Imperium and their homeworld in varying degrees.
The Vilani have had grav and jump tech longer than we have had the wheel, and the Geonee and Suerrat are in the same range.