I also vote turbo. The GN turbo is perfectly sized (3.8 vs 3.7 for 225 /6) and the GN guys get 10's on stock turbo. Set it as a blow through with 4bbl and a clifford or AussieSpeed intake, and use alky as intercooler, or blow through an Air to Air unit from Ebay.
The ability to slowly increase boost pressure while tuning the car offers far more adjustabilty then building a max out N/A motor.
Joshie225 and Shaker13 are 2 guys from slantsix.org that you need to involve if you go turbo.... I think Shaker's is the 12.95 video.