You can modify the circuit shown here http://playground.arduino.cc/Main/DIYRFIDReader to work at 134.2 kHz. The coil will need to have fewer turns so that the combination of L1 and C1 is "resonant" at 134.2 kHz instead of 125 kHz. There are standard formulas for the resonant frequency as a function of the coil inductance (which in turn you can estimate from the size and number of turns) and the capacitance of C1. Google "LC resonant frequency" and "coil inductance formula" to learn more.