I'll look and see what I can do in ME for power management and hibernation. First glance is it's not as easy as you say, but a second and third look are forthcoming.
I've bought the 325 and the 500 and hooked them up as I described above. The 500 has shut-down support while the 325 does not, but if I can activate the shut-down via the network that shouldn't matter.
Thanks, all!