what do I need for base?

The basslink is an ok setup.  They add a small amount of bass to a car compared to the space they take up (very small).  I would go with a bazooka tube before a basslink, but that's my oppinion.  Their new system has one ten and two passive radiators that can bump a little more then the basslink but you sacrifice some room (it's still small enough to fit behind a standart truck seat).  If you have the room and bout $300 to spend then get a traditional setup.  Go with a trusted name brand (just ask around to see what people say their's is) and listen to what you want.  Some people will say get 8 13w7's     and some will say a plain 10" infinity will do.  But like I said pick the one you like best.

I think that bazooka bass tubes are kind of wimpy and that a traditional setup (like the one i mentioned ) would sound alot better for about the same amount of money as the bass tube.