The LM350K will work for you, down to about 7.2V, however it it only rated to 3A. You can increase the current rating with an external pass transistor, or by parallelling two regulators.
The attached circuit should work. Be sure and use a heatsink for the IRFZ40 mosfet. The LT1054 doubles the input voltage to give enough voltage on the gate of the mosfet. The input/output differential can be as low as about 0.5 volts. The resistors on pins 5 and 6 of the LM723 are
2.0 k, but 2.2 or 3.3 k should work fine also