servo system limitations??

[nashyboy]

Hi everybody,
I am new to CNC machine building and was wondering if anyone can shed some light on controller limitations before I decide on a final system. I would like to know a couple of things...

1) Is there a controller available which will allow me to manually jog or control the servos without programming them (a bit like the manual controls on a commercially available CNC lathe - for example)? So I can choose the axis I want to move and fine tune it through manual jogging or even perhaps manually machine a piece if required. (I have seen a "joystick" controller, but i'd much prefer a "dial" which hopefully can be adjusted for slow feed up to rapid feed).

2) can two steppers be controlled through one channel? Eg. If I want to have two servos controlling one axis? Are there any limitations (Accuracy / torque) on this type of system?

Thanks for taking the time to read this, hopefully someone can help me out!