Shiro, for the region of Jilin province, you could have the Kingdom of Bohai (a.k.a. "Parhae" in Korean). The leader was Dae Jo-young who led the remnants of the Kingdom of Koguryeo (Koguryeo was conquered in Korea's Three Kingdoms Period). The region was home to the Mohe people, but I can't find any pics depicting the Mohe. They were conquered by Koguryeo earlier and was integrated into Koguryeo, so having a Korean-esque leader would work for them. The history of Parhae (probably a more proper term since Bohai is a Chinese term) is still a bit up for debate. The Chinese claim that Dae Jo-young was a Malgal ("Malgal" is another name for "Mohe," since "Mohe" is also a Chinese term) and that Parhae was a "barbarian" tributary state to the Tang Empire to deny connections between the Parhae state and Koguryeo. Then again, the writers of the history of the Tang Dynasty called EVERYONE else the same thing.

On the other side of the debate, the Koreans apparently contest that Dae Jo-young was indeed of Koguryeo stock and that the peoples that inhabited Parhae (now "Jilin" province) were both Koguryeo AND Malgal. Their argument is that "Dae" is a uniquely Korean name. Personally, I'd side with the Koreans on this argument.
There aren't an pics I can find online of Dae Jo-young, but he should look like a Koguryeo-era king, kind of like this guy:
Koguryeo mural
I don't know specific leaders for the Xianbei, Jurchens, and Khitans (all peoples that inhabited Heilongjiang region), but you could have a Manchurian king represent that region.