What kind of Speaker Box Should i build?!!?

Either way is fine. A wall is essentially a box with trim panels anyway, just positioned upright. In any case, try subs up port back as most tahoes get loud that way without walling. Hope you know what you're doing! :D

Since in your suburban your subs are going to be in the same air space with you, you don't need additional power from a ported enclosure. Also, ported enclosures are tuned to play one frequency, one note, louder than all others. For some music bands and styles it will work fine, for others it will be too much and you will have no way to adjust. I suggest sealed enclosure. It will take less space and play all styles of music and different music bands equally tight and accurate. Stay away from all symmetrical designs, they sound odd and unnatural. Also, if you are going build the enclosure yourself, the single box for all subs will require much thicker boards and additional structural reinforcements. Consider getting individual enclosures, one per sub. If you want it to look like one large unit, you can fasten them to each other and then upholster them as one large unit. I believe this will give you outstanding performance, loud, tight, and accurate.

i'm able to make the sphere for the 8" subs (with their own guy or lady chamber w/ maximum impressive airspace) with greater useful clearance on the aspects for 6x9 holes and then field indoors the backside of the 6x9's very final. fabric can help guard the sphere yet it somewhat is honestly own selection.