Methods and systems for accurate and precise fuel supply control for continuous-flow of gaseous fuel to an internal combustion engine over a large dynamic power range, including a dual-stage valve that allows optimal control—a first stage in the form of a voice-coil driven electronic pressure regulator, and a second stage in the form of a voice-coil-driven choked-flow valve; monitoring the pressure of the fuel intermediate the two stages and making appropriate adjustments to the first stage via a pressure actuator loop; feeding the gaseous fuel mixture through a unitary block assembly into the second stage; monitoring the pressure of the air/fuel mixture and making appropriate adjustments to the second stage via a valve actuator control loop.