You are describing a "kiosk mode", (see
http://en.wikipedia.org/wiki/Kiosk_software
)
and I agree that gOS seems to be perfect for an internet cafe with
it's large buttons it seems very inviting, and it will run very well
on low cost computers.
gOS 3 is still in beta, I think there should be a fairly stable
version first before adding the lock-downs needed to add a kiosk-mode
to gOS.
I have to say that I don't understand what you mean by WOL, (wake on
Lan perhaps?) perhaps you can clarify that point.