Controller for 8NM closed loop leadshine drivers

[JAZZCNC]

Do you want Control software which you use on a PC or dedicated stand alone CNC Control.?

The most common control used at DIY level is PC software based Like Mach3 or LinuxCnc. Mach3 is my first choice as it's better supported with users who speak in laymans terms rather than Geek.

Regards the Breakout board then with PC based then yes you'll need one as it makes connections easier and safer for the PC by providing isolation from return voltage etc causing damage.
If you do use Mach3 then I'd also suggest you think about using an external motion controller to get the very best from your system. They give far cleaner pulse stream than the parallel port so allow higher performance and more stable system. They also use Ethernet or USB connection which means easier connection, the other advantage is they don't need high spec PC as the Motion control card does all the Work. They also allow cheap laptops to be used.
They also allow more Input & outputs for connecting or controlling other devices.