I don't know if you want to hear this, but thats not it.
There is no reason in the world that if the hydraulic pressure was applied to pads and rotors in good condtion, they would not be able to lock up the front wheels. Same brake system (minus the booster) works well on my car and many others. I've locked up race tires (flat spotting is not a good thing!) so the system is capable - something is wrong.
I would investigate the hydraulics, the booster and linkage, as well as the rotor surface and pad lining.
Been through similar and there is no obvious definative answer from the info posted.
