The best thing to do is:
Go to a good muffler shop. Ask the guy to let you hear different mufflers on your truck. What he'll do is cut of the stock muffler then place different new mufflers in its place with tape and rags to hold it. The the guy will rev the engine through the different sounds each muffler will make. You just stand near the truck listening to each one.
You are the only one who knows what sound your looking for, so you judge them.
And remember, the loudest sounding muffler isn't always the best sounding muffler.
The exhuast guy will let you know what's legal.
Before you do this find a very good shop, chose one that does a lot of trucks and SUVs. Stay away from RICE shops. Remember when you do this, they're going to cut off your stock muffler, so be ready to pick and buy a new muffler that day.
By the way, where are you at in CA?