Like others said, I would check around at auctions and farm equipment dealers. Also ebay has them quite often.
I grew up using one and still do today. We used to have one that was on a trailer that ran off a belt driven by an old GMC engine. Now I use one that mounts to a 3 point hitch and is driven by a belt powered by the tractor's pto. I split all my wood to 4' lengths, stack it to dry, then cut it to stovelength with the saw rig. With a helper taking wood off and throwing it into a truck, I can cut a cord, 4x4x8', in about 45 minutes. They can be dangerous, but like anything else, you just have to be careful. Eye and hearing protection always, and keep the area where you stand free from small pieces, etc.