I have not seen a Spec V on the road yet.
I have not seen the HKS GT600 package kit in any shops around here yet.
SHH-Proshop Brunei has both.
The HKS GT600 Sport kit is named appropriately because it tunes the Nissan GT-R to close to 600 horsepower and 556 ft-lbs of torque. This Sport version contained the silencer instead of the straight pipe in the race version.
When i convert the kit to Malaysian Ringgit, it is around RM40k. Not including tuning i believe.