I did a quick search, and there's one on Aliexpress.com with similar specs to one you're looking for.
It's WM8650 with Windows CE 7.0
(I think it's Windows Embedded Compact 7?
)
I believe some of the members here have purchased it.
The price is $74.08 I never purchased or touched the device so can't comment on how the build is.
http://www.aliexpress.com/store/product/7-Mini-laptop-VIA-8650-800MHz-256MB-RAM-4GB-Nand-Flash-windows-Notebook/605114_383186964.html