AFAIK the only trim levels/packages ever offered in the 4th gen for its entire run were the SR5 (base model), Sport and Limited. I think the "Urban Runner" came along around 2008? and I think the Trail Edition (the only 4th gen ever available with a factory rear E-locker) was 2009 only.
So to answer your question, I don't think the 3rd row option is linked to any specific package. The 3rd row models also have a different 2nd row (with a seat that flips forward to allow access to the 3rd row.)
Of course, there's no foot well for the 3rd row and the ceiling height is fairly low, meaning that the 3rd row is for kids only. Also the 2nd row seats are fold-and-tumble, I believe, which means that even folded they will consume more cargo room than the 2-row models (which are flip and fold.)
Realistically, I don't think the 3rd row 4runners were that popular for a reason. If you really need 3 rows of seats, a 1st gen Sequoia is probably a better choice, IMO. Or, if you can live without that T emblem, you could look at an R51 Pathfinder, which has a pretty nice 3rd row setup that still retains some cargo room behind the seat.