Help to find the right HEMI swap harness

Hello, I wonder if you can help me with my project.
Basically I'm trying to run an HEMI 5.7 L V8 engine from a donor RAM 1500 year 2015 with 65RFE transmission (6 speed) to be mounted in my project (GMC Truck 1955).
The guys from Hotwireauto and Sublimeparts doesn't have harness + ECM capable of manage my HEMI + 65RFE transmission.
I appreciate your hints and comments.