I use the nova comet II works well plenty of speed and power for a mid size lathe. I think you can do up to 12 inch bowls but I’ve never done any over 8. And they make an extension bed for $100 that will extend from 16inch to almost 40 inches between centers. It also uses all common sizes for accessories and is adjustable speed. check it out here’s link https://www.amazon.com/46302-Comet-Bench-Package-Turning/dp/B0747LPDWL/ref=sr_1_2?ie=UTF8&qid=1514351570&sr=8-2&keywords=nova+comet+ii+lathe