With a little more research, I came across and even better idea. Perhaps you can find something like this, a Thermostat Housing Spacer. I'm not sure what the size of the threaded holes are, but it would allow you to put the thermostat ABOVE the two outlets, and thus you would get water flow (and thus heat to the heater core) out of them even if the thermostat was closed.
I can't give you the origins of this part, because it was just on a site full of pictures, not engine parts. But you get the idea, with a little bit of research you might be able to find something that would work for you.
