What size shamisen?


I am actually interested in getting a sanxian, the Chinese version of the instrument. It comes in 3 sizes. I play old time banjo and am looking for something comparable to ordinary banjo scale, which is the smallest size sanxian. I’d like to play old time on it, like Kyle’s video of house carpenter on shamisen. I don’t know what size to get or anyone who knows anything about the instrument. Do you guys in the shamisen community know?