Just an idea on the engine.
I came across a salvage Cobra today with a 5.4 S/C from what appears to be 2007+ GT500. Has a manual trans as well. Might be something to consider as it would have the harness, ecu, trans, throttle, accessories and also be a forged internals motor.
https://www.copart.com/lot/29351339
GT500 motor:
https://www.motorcarsofjackson.com/i...Jackson-MS.jpg