Here's the link, but it looks like you have already found it:
Vehicle Registration Fee Calculator (Used)
You will need the information it is requesting to calculate your potential fees.
Regarding the Nismo itself, if you have a seasoned mechanic contact that you can trust, I would have them inspect the vehicle. Also, a dealership can printout all the information on the vehicle, including services performed to date (summing the vehicle was taken to the dealership). Owners' are adding an oil cooler, and there is a Nissan oil cooler available.