A website for another 京A agent ...

http://lyja.58.com.cn/

I've heard this guy has a knack for acquiring / selling good numbers, if that is important to you. Personally, I've never inquired, although I suspect that premium numbers command premium prices. BTW, 66666 is coming up (if not already issued), as the 66nnn series started recently. I'd guess that the Harley dealer will somehow grab it.

Oh, and Beijing's policy about 47nnn being foreign-owned has stopped - foreign-owned bikes are now just "regular" numbers, and 47nnn plates can be owned by resident Chinese. It will probably take a few years for this to run its course.