Dave, I only know of one guy who makes dedicated pen lathes. Most just use a mini wood lathe. I have one I paid $100 for.
Check on EBay or Penn State. They have pen mandrels and kits. The pen mandrel will fit in your head stock and tail stock chuck.
Use a piece of square stock in a tool holder for a steady rest.
On EBay, you can get a small set of turning chisels or even a small pack of
carving chisels can work. They have gouges, skews etc, everything that you need to turn a pen. Just a thought that might save you the price of a mini lathe.