Replacement Muffler Suggestions?

I have an '02 Sierra with the 4.3 liter V6. I recently purchased the truck, and it came with a muffler that splits into two seperate tips out back. It's louder than I want since I do a ton of highway driving and the low moan of the exhaust on the highway makes me tired.

Does anyone have a good suggestion for a replacement muffler? I would prefer something that breathes well, but isn't loud. Factory quiet preferred.

Oh yeah, and those tips are going away!

God, I'm only 27 and this post makes me feel like I'm 50 something.

I replaced a similar loud system on a '92 Sierra 4.3 with a stock replacement from Midas. I had also grown weary of making trips with that roar. With the loud system gone, I was able to relax and enjoy the scenery or listening to the stereo on those long trips.