You haven't received any responses to this yet so I thought I'd throw in my two cents.
When I was confronted with the a similar problem with my Suburban, I found what I needed at WayTekWire.com based on watching the Mike Finnegan videos on YouTube. Here is a link to all of the power distribution blocks they sell
https://www.waytekwire.com/products/...s/&pageSize=36, you'll have to figure out which suits your needs.
Myself, all I wanted was a fused higher amp relay to provide key-switched power to a new fuse block I installed in the cab to run stereo, radio, power supplies etc. and I chose the
Eaton Bussmann 70a 37702.
The
power distribution section has a large number of options, some of which cost hundreds of dollars and appear very similar to OEM boxes found under the hood of many modern vehicles. Perhaps one will suit your needs.