New to this, have some wiring questions

[dmsir]

Recently picked up a 1970 chevy k20, it only has the 13 slot tube fuse panel, it has a "stock" am radio in the dash but no wires to it (or the cigarette Lighter) and there are no speakers. I'd like to get some tunes going(nothing heavy duty looking at a 4 speaker and head unit kit for $129) as well as putting on some extra accessories (cab lighting, bed lighting Etc) How hard would it be to rewire the truck with an updated panel? would i have to rewire the whole truck at that point? or should I just add a fuse panel in the engine compartment and run wire from there? any help greatly appreciated

Edit: I should add that i looked for the radio and cig lighter wires to see if they were tucked away but i didnt see any