Yes, your English is very good.
It would not work to get seeds from individual cultivars, they would not come true to the parent. The only way to get each one is by offsets, the offsets are exact clones of the parent rosette.
I don't know of any sempervivum nurseries in China.
SMG might ship to China, but I think it would be very expensive.
You can email Don Mylin and ask if he would ship to China.
http://www.smgsucculents.com/s...
https://www.storesonlinepro.co...