That's a tough question to answer. You can find them in many places - used gun dealers like Puglisi's. Take your big checkbook. I think they might still make them in Russia as single shots.

Not sure why someone new to shotguns would want an 8 but I will assume you are a rock star of some sort known for extravagant ways and owning an 8 will only serve to fuel that image. I suspect you'll deny it all, but that, in turn, will only serve to fuel the image even further.