I have an 80G SCA cube which has the same plumbing. First thing first, throw it all away. It's metric, and a pain to match up when you have an emergency.
Then go to lowes/HD buy the same parts minus the bulkheads. Then just as it's layed out above, plumb it that way. I used one strainer in the full siphon line(shortest pipe), and the rest are extra. I also do not use the down elbow on my emergency, I just leave it an open pipe, The top of the emergency(right pipe)sets the height in my overflow. Returns up the middle, split with the locline out the sides of the acrylic overflow.
EDIT:
My tank is 8 years old, they made have made the switch to standard plumbing for US based customers. Just check it with a normal standard fitting to see if it fits.