Since yhis is a street car, and won't see a road course, skip the
oil cooler. You'll never need it. It adds weight, complexity, and more leak points. It usually drops the pressure a little bit, too.
The simplest method is to use the sandwich plate, and one on line. And that's what you want - simple.
The check valve is used when you plumb the Accusump into the loop with a cooler line. Otherwise the
oil will follow the path of least resistance - back to the pan.