Yes there is electric boost. It was used where there was cramped space under the hood in the normal area of the master cylinder. I first saw it on a Jeep Cherokee.
This is not something you would want to adapt into a project. Hydroboost itself is a fabulous mature design when it uses a power steering pump to supply the > 1000 psi fluid pressure as the boost power source. The problem with the electric driven pump power source is that the pump design is below poor.
They chose to use a very cheap electric brush motor that is below the quality of say a electric window motor. They were not careful with fluid connector choices, pump body was aluminum, etc. The pump would strain to reach the design pressure.
How it was supposed to work: The pump would come on and pump fluid until a pressure switch was satisfied at 1200 psi. The pump motor would shut off until the pressure dropped back down (the brakes were pressed). So far things are ok until: Something leaks, the cheap pressure switch contacts stick or don't make, fluid runs low and the system stays on until the motor smokes or the pump gets hot enough to melt the "o" ring seals. The units are more expensive than power steering systems because they are constantly failing so the supply of rebuilds runs low and the supply of "cores" run low - driving the core charge through the roof.
I had considered using the brake fluid pump from an ABS system as a power source because they are good quality but, decided not to chance using a motor /pump that was supposed to come on a few times a year for continuous use. Stopping is just too important.
Hydroboost - Yes *** electric boost no!