Lead Screw vs Ball Screw

I want to replace the lead screw from a 5' X 8' Router's Z-axis, with
a Ball Screw and I have some questions:

What's the difference between Standard ball Screw and Preloaded Ball
Screw?

Do a 5/8" Ball Screw have the same performance as a 5/8" lead screw?

How to ask for a Ball Screw to get the same as 5 treads per inch in a
lead screw?

Raul