I suggested spacers because he was saying he wanted the Nismos. I agree with you that if looking at other wheels the offset is key and its always better to get the right offset than fudge it with spacers.
On the other hand, provided you get good hubcentric spacers from someone like Eibach you should be fine. For all the old wives tales about additional wear on the wheel bearings I'm yet to actually find someone who has had a problem.