Recommendations on a muffler for a '00?

Hi. I have a friend with a '00 Malibu. It's automatic and he's looking to get a muffler. He heard the Dynomax Super Turbo Muffler that I have on my '01 PT Cruiser and wants one that sounds similar to it. Does anyone recommend a muffler with a deep sound but without that bee like rice burner sound? Does anyone know the dimensions of the stock exhaust? I searched around a bit but couldn't find anything. Thanks in advance!

the malibu is a family sedan with a stock muffler that will last forever. Why would you want to mess with that?

Well, I'm not sure if I mentioned this in my other post, but he wants a better sound from it. I'm sure the stock muffler is great, and I'm sure there's nothing wrong with it, but he wants a different sound from it. Does anyone know the dimensions of it? Thanks again.