I have decided on my tempest sonotube design. 175L, 18" sonotube, 45" length w/1.5" endcaps, 64oz polyfill, (1) 4" flared port 13" long tuned to 17.5Hz. Dan has helped me with this design. My question is, are all 4" flared vents the same? I could buy the Adire kit, the Lightning audio kit or the PE aeroport kit. Should I just go with the cheapest one? Is one stronger or better than the others? I have never used a flared kit before so I have no idea. Thanks!