Based on the intended use environment and requirements, first determine what mode is needed (e.g., DMR, D-STAR, C4FM). Then, consider the installation environment: will it be used at home or in a vehicle? If for a vehicle, separate panels and speakers seem like good options. Also, consider whether APRS functionality is required.
DRM: Hongke 9100
D-STAR: There are few repeaters available in China, so there aren't many good options.
C4FM: The 300D, 500D, and 510D are all good options.