Stock back space is 4.5" and the Moto wheels are 4.53" so you're good there. I think the 97 OEM wheels are hub-centric and use shank style lug nuts. If the wheel bore is larger than the hub diameter you'll just need acorn style lug nuts.
Can you tell me if the wheels you ordered fit ok? I just ordered some new wheels today for my 97 and they are 106.25mm and I'm worried they might not fit. I was hoping to find out how your wheels turned out. Thanks