David, it depends on what type of music you listen to but without knowing that I would recommend either the EBS or Adire alignment. EBS will be the better of the two but at the expense of a larger enclosure.
With my brothers also using it, there will pretty much be all kinds of music being played. Can anyone explain what the Q value is for. That way I have a way of knowing what I am looking for. Also, how thick should the walls be in a traditional cube style.
David in general Q is a proxy for the sound of the sub... subs with a Q of .707 are generally considered a good ballence beween performace and sound quality with lower Q's being prefered for music.
As far as wall thickness it depends partially on how much internal bracing you're doing. Generally though I'd do at least 1" on all walls with 1.5" on the driver and port side