hes not concerned with Db's
i wouldnt waste money on those unless your riding in an area that has noise restrictions.
Your silencers are fine probably. You could easily polish those things up nice, repack the silencers, and seal the stingers to the silencers with o rings like they are suppose to be so you get a good seal and possible replace the rivets at the end where the stinger connects.
if you wanna polish your silencers, get some 1500, 1000, 800 wet dry sand paper, start with the 800 and finish with 1500, then polish them with 00 steel whool and polish with some mothers and a rag, they will look real nice, even nicer the more time you put into each step