Newbie question on Ballscrews....

Hi all.

I recently bought a new 2hp Grizzly mill/drill, and would like to
convert to ball screws in preparation to a CNC conversion

1. Could you recommend a particular style, brand and where to get?
2. What kind of quality do I need to keep .001 or better in a 6" or
so work envelope?
3. If I buy a ballscrew, what to I do with the ends where it goes
into the blocks on the mill? Are the ends turned, or do I need to
modify the ends somehow?

Thanks for your input in advance!

Dave S.