I tested all of the electronics first by wiring the PIR sensor and mosfet to the Arduino nano. A 5V 2A wall adapter was wired into the inputs of the mosfet, and I also wired the Arduino nano directly to the input ports of the mosfet. I used a single LED as an output to test the system. After the motion control worked and illuminated the LED, I went on to wiring all of the LEDs inside the PVC pipe.
I took two strands of wired and tied a weight to the end of them, dropping them through the PVC pipe, so that I had a positive and ground wire running the entire length of the pipe. I then took a hook, and hooked the wires through each individual hole along the pipe, leaving a 4in tall loop at each LED hole. After all the wires were looped through, I cut all of them and wired them accordingly to the LEDs, with a 220 Ohm resistor on the positive end of the LED. I wired the pipe in sections, with a T joint in the middle of the pipe to prevent sag and in order to make it easier to transport.
I used an extra cardboard box as a temporary enclosure. I cut a hole in the end for the PVC pipe to feed through, a hole in the top for the PIR sensor to stand out of, and small holes in the side of the box to run the power wires.