Lots of Rigs...
Hello Doug,
It really depends... What type of lathe are you turning on and what type of hollow forms do you plan to turn? If you have a small, or a mini-lathe, your choices will limited to a few different tools. On the other hand, if you are working on a medium size or larger lathe, you will have lots of choices.
Also, the types of hollow forms you wish to turn can have a significant impact on what we may recommend to you. Do you want to turn near the maximum capacity of your lathe (for example 3 feet high, by 2 feet in diameter), or do you prefer smaller more elegant hollow forms, like 10" - 12" high?
In my studio, I have lots of hollow form turning rigs including the Kelton, Oneway, Sorby, Jordan, Jamieson, Bosch, Pencil, Monroe, Hamlet, Woodcut, Stott, Berger, Stewart, Misc Boring Bars, Sudol Bars and a couple of home made set-ups to name a few.
If you can give me a better idea of what your goals are, I will be happy to recommend a few systems for you to investigate. Thanks and all the best to you and yours!