NAS Adapter using only Flash Storage

Hey,

my company is looking for a NAS Adapter using flash storage (USB-Stick, CF-Card, ...).
Using a HDD as storage media is no option because rotating media would result in problems at the installed places.

The NAS is to be attached to an ethernet and a embedded system running Linux is supposed to use it as Flashmemory.
So the NFS protocoll would be quite important. Speed shouldn't be too bad eather.

I read through the reviews of the
TRENDnet USB 2.0 Network Storage Server
and the
Network Storage Link for USB 2.0 Disk Drives
on www.tomsnetworking.com

The Problem is both of these product have a low transfer speed and don't support NFS just Samba.
Are there any better alternatives?

I would be thankful for help

Greets David