What wiring harness should I use?

[White70C20]

Hey all,
I'm starting to work on my grandfather's '70 C20 again now that I'm back at school. While the engine is out and the interior is stripped, I thought now would be a good time to work on the wiring. When I parked the truck back in November I checked to see if any of the lights worked. Nothing worked. I'm thinking either there are tons of bad grounds (unlikely), or the mice had lots of fun tearing it up over the course of 20 years.

Anyway, I was wondering what the rest of you have used for wiring harnesses? I've found replacement wiring kits from LMC but they're terribly expensive. This isn't going to be a show truck (it's full of dents), I'm just wanting a reliable daily driver. I was wondering if there were other, cheaper alternatives.

Thanks!