Really depends on the make, you can get Mitchell and AllData prior to the subscription model (takes about a TB of space, from 1980s to 2013) to help with diagrams and disassembly and reassembly. Mitchell’s wiring diagrams really are a lifesaver.
Dealer level software/scanner combo you can get from obdii365, I got a Hyundai scanner from them and it worked well but you want to run the software in a VM or isolate it some other way and probably wouldn’t network it.
Vxdiag is pretty solid as well for the dealer software/scanner and you can usually get via Amazon but again I wouldn’t trust the software. I have their ford one and used it with IDS to set the VIN on an electronic power steering rack.
The software itself you can find via Google if it’s all you need but typically the scanner is very specific to the software for the dealership stuff
This is pretty great advice to get into it. I previously ran 3 poweredge 2950s but have since switched to nothing self hosted and back to everything self hosted but on a much leaner setup with a NUC and 14tb WD my book drive with a dual Noctua 4020 fan shroud I 3d printed that it absolutely needed as I killed the original drive in two weeks.
My replica is just a 14tb in my desktop I run rsync to pull the data occasionally after checking SMART status on the primary. It’s not versioned or perfect but it works great to give me a chance to backup my jellyfin media. Everything I care about also gets backed up via restic.
Eventually plan to run a build with the Modcase MASS with multiple drives but for now this setup has been working fantastic.