How to make the truck a bit quieter without sacrificing character/performance

[futon]

Recently purchased '98 B4000.

I don't have a lot of detail on the exhaust equipment make and model, but I know the previous owner installed:

• Two high-flow cats
• A muffler that's barely wider than the exhaust pipe
• Vibrant resonator
• Dual 3" exhaust

Truck also has a K&N air filter that's likely contributing.

The resonator makes my head explode at 3000rpm.

Should I replace the muffler first? If so, what would you recommend?

Restore the factory airbox?

Thanks