Stand-alone wiring harness for Allison rds4500

I am wanting to put Allison rds4500s in two of my dump trucks. One is a 99 379 with a Cummins n14 the other a 2000 w9 with a cat c15. Both could have come out with automatics however I can’t find anything similar at a salvage yard to get the complete system. I talked to someone at Allison trying to find out what tcm I needed etc to try and source everything separately but they weren’t overly helpful. I know you can get a stand alone harness for Allison’s out of Chevy trucks but haven’t found anyone making them for the larger Allison transmissions. I would like to find some place that makes them or someone with the knowledge to do it. Or someone who could tell me the correct components to get to put it in as an oem installation. Also what gen transmission would be the best and easiest for the application.Any help is appreciated.