Battery positive wires

[firebirdzig]

I was looking for some different options/ advice on where to hook up all of my battery positive wires (fans, compressor for air bags, door locks ect). I was going to run a battery cable from the starter to a painless junction box with 8 terminals for battery positive wires to u Del the dash. I don’t think I’m going to be able to get a second 1/0 size wire on the starter. Can I run a smaller wire? What are some other options y’all have done on your cars? Thanks