I have a setup very similar to what your looking to do.

Meagan o2 house
Meagan downpipe
Meagan test pipe HKS mid pipe
Stock Evo 9 muffler

It did quiet the car down. But only SLIGHTLY. The biggest improvement is that horrible droning is gone. I made no mods to the muffler. Simply cut it off and welded on a 3" flange to mate to the HKS mid pipe. I tried the DynoMAX VT muffler buty cams would make the flapped bang every time they loped. Really annoying. The car does feel a bit a restricted and my mpg went down a tad. But I feel like its totally worth it for a DD

 

only thing i worry about is restriction, i have both stock 9 and works muffler, any opinions on which one i should put on? i love the looks of the works! and hope it will give the car deeper tone and no drone . thanks guys for the help!