Arduino to control a 6 dof motion platform

Hi everyone,
I want to make a 6dof motion platform using 6 Linak LA36 actuators. I have a software getting data from the simulator on the pc and calculating the output of each actuator in real time. If my understanding is correct, I need 6 PSU and 6 motor controllers and an arduino bord that connects to the pc via USB.

Now, what bord should I be looking for? Do I need 6 bords?
Any explanation about this setup is of interessert. Is the code as easy as I think it will be.
Arduino should get those data and then output them to each actuator.
I will using the motion simulator for racing and I need to minimise any lag factors.
Thanks in advance.