If your doing long thread lengths of 8 to 16 inches of thread it is all according to how much money you are willing to spend. h**p://www.landisthreading.com/ will probably be your cheapest way to go. As far as threading you cant get much better than Landis. As far as high speed threading you can spin this head pretty much as fast as you feel comfortable with , We have been threading bolts and rod for twenty five years and these heads give good service. If you want to go one step further you can get a through feed threader (h**p://www.tesker.com/) is the Cadillac of these type of threaders but are a lot more pricey and without experience the Landis head will give you better quality and less maintenance.There are companies that have produced sag rod threaders but the tonnage you would need to do that much thread in one pass would be as big as a small warehouse. The machines i have seen were capable of doing six to seven inches on both ends at one time. Do a search for planetary roll threaders and you should be able to find something . If you want to ask more specific questions please feel free to shoot away as i stated before I have been in this field twenty five years.