My 9x24 southbend is about the smallest you'd ever want to consider, as I'm not always able to get thicker barrels in the headstock. You'll want a quick change gear box for cutting threads, a steady rest for chambering, and a 3 and 4 jaw chuck, as basic tooling. A set of collets and closer, milling attachment is always a plus. I'd like to have a 10" or 13"southbend myself.