Chinese and original....both are different in structure.
if original used parts are in good nick and not repaired, you can verify them by visual examination after opening it up, then go for original used part just because it is well built as compared to Chinese ones which are cheaper even being new caz of lighter structure.
do remember to use original new axle grease in required quantity, 90g i think is enough, also do remember to take as much as u can while installing rubber boot.
infact u can get axle grease tube and grips from new axle boxes and use them with ur verified axles...
do verify the rubber boot because damaged boot is the major reason behind axle failure.
P.S. if you can source genuine new part, then nothing like that