Before you go spending your cash you need to have a good thinkabout what you are going to be cutting and how much you will be using the plasma power source. Alot of the smaller portable plasma will not have a high duty cycle so this will limit the amount of arc time you get. You might not get "hold" or "delay" contacts from the power source to connect to your cnc machine. These contacts normally allow the plasma power source to pierce through the material and ramp up the current to the set level required for the material thickness before allowing the cnc machine to start motion. Also they wont have any Arc Voltage Control systems. This allows the plasma unit to monitor the arc voltage across the plasma arc then adjust the height of the torch holder, ie the Z axis, to keep the cutting height the same. If you dont have this you will have to watch the cut continually to make sure it stays roughly the same height. If you are doing this you need a full face helmet with a good quality glass it in to stop damage to your eyes and skin from the plasma arc. Decent gloves as well. A fume extraction system is a must, plasma fumes from cutting are lethal and you should filter the fumes as well to remove particulate matter before dumping it to atmosphere. I will presume that you will be cutting air plasma/ air shield which is using compressed air for the plasma and shield gases. Your air supply needs to be oil and water free for the plasma to work correctly.
John, the Cebora plasmas were dodgy and expensive. I also remember looking at a small profile machine which sat in between two Miller snycrowelds. When they fired up the poor cnc controller went nuts due to the RF.

Ian