[XCSSA] Tips for DIY NAS?

[X-otic Computer Systems of San Antonio]

I was checking out CPU magazine on the plane ride home today and was  
reading up on commercial NAS solutions. They all look pretty cool but  
seem to be very expensive or not configurable enough. I already have a  
nice LSI SATA-RAID (4-drive) and, in fact, already have a file-server.  
The problem is that it's loud and consumes too much juice. That's one  
thing the commercial solutions have up on me - power usage.

I've been trying to piece together a VIA C7-based machine, but all the  
boards I have found seem to be too small. I actually would love a MIPS- 
based solution (just because I jones for RISC :) but I have found even  
less info about that.

Granted, all I need is a PCI/PCI-X slot for the controller, but I'd  
like to have a 1x PCI-E slot for future expansion. I was also thinking  
of having it boot up off CompactFlash or something else that would  
otherwise allow me to keep the RAID separate from the OS drive.

Any thoughts?

Tim S.