The size of the lathe you get will pretty much dictate the amount of material you can remove quickly and also leave you with a good finish. I have heard a lot of good things about the Taig lathe and the big bonus with it is the accessories are very reasonably priced and easy to get hold of although I do not have any personal experience with one.
here is a link to a guys clock building project where he is using a Taig.
Do a bit of research before you take the plunge but I cant think of anything better for the money. The Emco Unimat 3 is another popular clockmakers lathe but again you will have a hard time finding accessories and it will probably work out a lot more expensive than the Taig.