I'm coming to the conclusion that the most sensible approach for my 'garage server' will be to build it myself.
A Mini-ITX system would be ideal but the prices are still silly compared with boring old ATX and ATX related systems. In addition I have an ATX case that I can use.
Size isn't an issue, I have two huge garages. Noise isn't an issue, I don't sleep in the garage or watch TV there. :-)
So it would seem that a motherboard with an AMD BE series processor would give me a start for a low power system. Is there any way to decide how power hungry motherboards are? I'm open to alternative recommendations for the processor but Googling about suggests that an AMD BE-2400 or something like it is probably the best low-power/price compromise, so I'm looking for an AM2 motherboard with video and ethernet on board with low power consumption.