Stock Exhaust and Cats

[KMK454]

First post in a while! The truck is coming out of storage. I do not need to "smog" my truck, but would like to clean it up as if I had to smog it. Eventually this means getting the charcoal canister and other stuff refreshed, but the first (and easiest) target is the exhaust.

Right now, it has LMC manifolds into true duals (no cats) that dump beneath the bed. The truck is a 78 C10 305 V8.

I would like to get a stock setup with a cat(s), manifolds and proper exits like the truck originally came with. The LMC manifolds should be fine, but I'm at a loss for the rest. Does anybody make repro parts for this? Or would I have to have one fabricated based off the brochures and documents with the truck?

Thanks!