Just got another one of these cards off E-Bay for $20.00 + S&H. Easiest embedded PC to set up ever. Plug in flash card with boot rom and OS, off you go. These kinds of no-fan systems usually have a MTBF (Mean Time Between Failures) of 100,000+ hours or around 12 years you can run them without interruption before some component will begin to misbehave. Probably it is possible you might run one 20 years without ever encountering a hitch and if you did it would likely be something you introduced in software.
Average specs is something around a Pentium I/II with 32 mb SDRAM, PCI/ISA bus, 4 com ports and one parallel which is more than enough to control anything.
Because almost all PC/104 units have a watchdog function, you can always recover gracefully from a crash with a reboot automatically and if your software keeps track of it you can run self-diagnostics and log anything out of place before resuming.
Something like PowerBasic is ideal for these cards but you can run GEOs Ensemble or Win98/SE at a good pace with all the functionality that entails. IPX is still an excellent basic communications protocol between all terminals because it is so simple almost nothing can go wrong.
I was thinking of making this unit the dedicated controller/terminal for power management in Sparkgap, as well as managing water and fuel pumps from the silos farther up the hill.