2005 Silverado Exhaust

I have an exhaust question for you guys. I have a 2005 Silverado 5.3L stock exhaust/ AirRaid intake. I wanted to make it a little louder and sound a little better but not to the extent that most of these trucks with aftermarket exhaust. I would like maybe halfway between the stock and loud aftermarket.
Would adding a flowmaster or magnaflow muffler and leaving the cats do what I want or would I just be wasting money? The reason I say this, my experience with a mustang was the flowmaster actually made it quieter with a deeper sound until I removed the cats. This is not what I'm wanting. I want a slight volume increase, better sound and leave the cats and single stock tail pipe. Is this possible?

I have an exhaust question for you guys. I have a 2005 Silverado 5.3L stock exhaust/ AirRaid intake. I wanted to make it a little louder and sound a little better but not to the extent that most of these trucks with aftermarket exhaust. I would like maybe halfway between the stock and loud aftermarket.
Would adding a flowmaster or magnaflow muffler and leaving the cats do what I want or would I just be wasting money? The reason I say this, my experience with a mustang was the flowmaster actually made it quieter with a deeper sound until I removed the cats. This is not what I'm wanting. I want a slight volume increase, better sound and leave the cats and single stock tail pipe. Is this possible?

I can't speak for the 5.3, but I own a 2005 1500HD with the 6.0L. Had the original muffler removed and installed two Flowmasters to two tail pipes. Looks and sounds good.

I ended up going with magnaflow. They make a 14, 18, 22, 24". I ended up going with he 14" due to mechanic recommendations. I really love the sound when I crank up and accelerating but does produce more drone than I expected at 1700-2000 rpms. This can be an issue especially with 410 grears. I thought about replacing with a longer muffler as magnaflow rep said it each step up reduces noise by 10%. Only thing, I would hate to reduce the non-drone noise it makes. Decisions...Decisions...

Also, as an FYI- When I installed the Air Raid Cold Intake a few years ago I gained about 1 mpg in fuel economy. After adding the MagnaFlow muffler, I gained about 1 1/2 mpg more. I averaged 12.5 mpg stock and I'm up to 15 mpg and this is without keeping my foot off the throttle from the new sound.