Hi I'm thinking of getting an exhaust system for my NBS 2007 VMax 6.0 LTZ. I only want to give it a better, more aggressive sound when on the gas but want it to still be relatively quiet at highway and normal driving. I also do not want a highway drone and want the new muffler to work well in 4-cylinder mode. I believe the most economical way to do this would be to buy an aftermarket muffler and get a system made up at an exhaust shop. Any suggestions or recommendation on what type of muffler I should use?