Drivers depend on the steppers you are using, you can purchase a kit containing most or all of what you need, like this http://www.xylotex.com/3AxSysKit.htm or this http://www.hobbycnc.com/hcncpropkg.php
1. what kind of Stepper Driver,and electronics do need for this design?
From what i've seen, it can be either, but most seem to go for one like the one's listed above.
2. what controls tr he 3 axis, one unit or 3 controllers?
You can use TurboCNC "Dos based", or Mach 2/3 "Windows based", I'm sure they might be a couple or so more, but these are the most popular, most cater towards Mach 3.
3. what sotware do u use to controll it?
Well sorry I can't help you there, but if you keep looking around the zone, good chance you might find, or someone can answer that for you.
4. does someone hve a detail electrical schematic for the above, how the Emergance stop wired in, are the limit stops?for the unit?