NASLite works well (Score 1)

It is based on a recent version of the kernel and has good support for hardware RAID controllers and Gigabit NICs. The cost is very reasonable. If you don't want to spend the bucks for hardware RAID, it also supports once-per-day disk mirroring. I'm using it with an old Pentium III box with excellent results.

http://www.serverelements.com/