It depends on the circumstances. If your idea of an electrostatic drive engine is to have the electrostatic drive accelerate really small "vehicles" then sure, you can buy them right now. But you may need a microscope to see the "vehicle."
For a larger object it is hard to manage the electric field needed to suspend the object without breakdown of the air between the two sides of the electrostatic field region.
That's may be less of an issue in space, so an electrostatic hover board might be easier to build for use on the moon. Until you find out what the dust does.
We shall see. Supposedly, the US government has been trying to back engineer recovered UFOs for decades with minimal success. Then again, maybe they want us to think that their success has been minimal. In the meanwhile, I go into the backyard every time there is a launch from the Cape hoping to catch a glimpse of the rocket climbing to orbit.