Sambo
A number of Harrison's builders (including myself) opt to get the front rotors redrilled and the studs replaced with nissan studs. This means all PCDs are the same as are the threads on the studs.
I have even gone so far as to procure a space saver wheel from a Skyline!! Although as Craig has pointed out, I am not too sure how the 10" with a flat will go in the boot!!!
I am currently in the process of purchasing wheels and the offsets I am using are 135 (rear) and 90 (front) - by advice from Warwick himself. This does not take into account the *tyre bulge* that will set these back a little further, depending on what size rim and tyre you are running. I am planning on running 225/50x16s and 255/50x16s on 8s and 10s respectively so I reckon about 10mm will be enough. Hence I have ordered offsets of 125 and 80. If you choose to run with 17 or 18s, the bulge will be less and if you want 15s, it will be a bit more I am guessing. You can run 15s on the Nissan rear end, you just need to have some mods done to move the caliper closer to the wheel centre - the recently finished Daytona has 15s all round.
Hope this helps
GeoF