NXP MPVZ4006GW7U as Breath Sensor/Controller

Other Hardware Sensors
5

If you have a bare MPVZ4006GW7U, then use that one.
It has a built-in instrumentation amp, and can be connected directly to a 5volt-logic Arduino.
Likely better quality than the ones mounted on those red boards, although they work fine.
Mount your sensor on a piece of strip board, and simply read it's analogue value.
Post a picture of the build.
Leo..

Edit: added some test code for that sensor.

const byte pressurePin = A0;
float sensorType = 6.0; // kPa
const int offset = 54; // zero pressure adjust
const int fullScale = 970; // max pressure adjust
float pressure; // final pressure

void setup() {
  Serial.begin(9600);
}

void loop() {
  pressure = (analogRead(pressurePin) - offset) * sensorType / (fullScale - offset);
  Serial.print("Pressure: ");
  Serial.print(pressure);
  Serial.println(" kPa");
  delay(500); // testing only
}