Anything is possible! If you have the resources to do all that you will be able to SAVE.
I donít believe that the machine you have came with ball screws but I donít know that. In any case, there are hundreds of suppliers just search for Ball Screws.
What you are looking for is the precision ground type of screw with anti backlash nuts (very expensive) they generally have an accuracy of .0005 per foot. They will be somewhere at 50 Ė 65 Rockwell make sure you can work with that!
If it was me I would not settle for less. Also read about the difference between steppers and servos(very important to know) I will give you a fair warning about most of the cheep steppers floating around on the web, donít buy them!
Steppers will get hot!! Most manufacturers donít recommend running them all day.