If you want something very quiet you should try the new Disrupive death touch barrels. Its got an whole 8 inch control bore and reverse threading like planet eclipse.
I have the first kind of disruptive barrels and you wont find anything quieter. Very nice barrels.
The new death touch seems to have the same porting as the original and should be just as quiet.
Macdev Clone VX Black/Aqua
Crossfire 68/45 LP