I reckon stick with the 460 and freshen it up, maybe retrofit an OD trans to it.
Otherwise, **** Coyote, go Godzilla:
https://performanceparts.ford.com/part/M-9000-PM73A
$20,000 USD ex shipping and import duty, but includes:
7.3L Godzilla
PCM/
TCM controls package
10R140 10sp auto
Accessory drive for engine