The Mappit system recently reviewed on the SPCR main page would be a good choice because its sealed so your dusty environment would be no problem. but it does not have a PC card slot.
Well i might have to correct you there flyingsherpa. The Mappit A4F is available with the MII 10000 motherboards from VIA! Which is the one with the PCMCIA slot at the backpanel. As we said at the end of the review, we can customise the A4F to meet almost any needs. All of the VIA EPIA motherboards can be fitted into the Mappit - the desktop and rackmount version.
With customising we mean that we even make the frantpanel without any opening or even a power switch (always power on) - this makes it even better for a dirty environment!
If you have any further question don't hesitate in contacting us via http://www.ramlowdesign.com