I will double-check, but I believe
this is a very good aftermarket replacement that matches the original very closely for $18. It's even made of metal like the original fan. I think the original fan blades were slightly bigger, but this replacement spins slightly faster (2,000 RPM).
As a comparison, I found an original OEM version of the fans a few years ago and they were asking close to $100. So... yeah.
You can watch someone installing this fan in their own A1000
here.
I haven't done this upgrade myself personally. I've been thinking about it, but wanted to see more on this fan first as it's not silent like the original.