As soon as you put on an open element filter and a hard intake pipe, the BOV will be loud (IMO).
You can pick up the MR valve here;
http://www.machevo.com/jdmevomrcoby.html
As far as other addons;
http://www.evotuners.net/tuning-guide/stage1power.php
You can pick up the MR valve here;
http://www.machevo.com/jdmevomrcoby.html
As far as other addons;
http://www.evotuners.net/tuning-guide/stage1power.php