The small hose coming from the fuel rail comes off of the fuel pressure regulator. it connects onto a small hose barb that comes off of the side of the throttle body.
Although I have left my heater intact, I would just try to connect the inlet/outlet coolant lines to the ends of the metal tube that runs through the vacuum lines. It seems good to do it that way just to keep stuff tied together. However, you could just connect a hose straight to the inlet/outlet.