Autometer, ISSPRO, and up until they started going out of business DiPricol are my favorites. I would recommend a 0-60PSI boost gauge and I always drill and tap for them right at the Y-bridge (after the intercooler right before the air goes in the motor) so you are actually seeing what the motor is getting. As was said an intake that deletes the resonator and has an open filter element will make it louder, but I personally don't like open filter elements sucking hot air under the hood - I prefer S&B and Banks sealed box intakes.