Those aren't encoders with stepper motors, those are servo motors with external potentiometers.
Using optical encoders gives me two problems - missed steps (which I've always had a problem with), and no memory on reset. I know I can interface with a RAM, but that still doesn't eliminate the missed steps issue. Plus if I have to get a robust stepper motor and driver, that adds cost anyway, and might justify the triangulation method. The idea of using a triangulation method, was that the device will knows its exact location all the time.
Also I was hoping for a more plug and play solution for the table and motors, cause I don't have the tools or the time to do much building on my own, and just have to worry about mounting the sensors, and the closed loop - read data from position sensor, move table based on data, repeat.