I wouldn't glue the ports. If you glue then then they are permanent. Use duct tape, metal screws (through the coupling), or a combination of both so that you can retune the box if needed. I would do 3 or 4 6in aeroports, not pvc alone. Some of the guys over at Termpro have tested with and without the flares, and the flares easily add a couple dB's of sound pressure.