They are Kicker Subs dont remember the model numbers though. I also have that 4 channel Alpine amp running the all my speakers.
The boxes are made/molded to fit the ST's, the back side is completely fiberglass, I have a write up somewhere and it shows how to make them. The only wood is the front and sides. They are held in by the "L" brackets at the top and fit tight at the bottom. They are sealed with the stuffing inside of them.
I was suprised how hard (2) 8's would hit, I actually have them turned way down.