Basically the standard top that comes with the DDC is totally injection molded and is what gives it the dual sideways barbs.
The XSPC Restop mounts to the top of the pump after you remove the stock top, just 4 screws, and make sure you keep track of the o-ring.
That then coems with the real screw in metal barbs and serves as the reservoir for the loop as well as improving the pumps performance.
Half inch tubing is pretty standard, make sure you get thicker walled tubing, ideally it's sold as 1/2" I.D. 3/4" O.D.