newer style 2004> engines sound very nice with an induction kit, older style one sounds ok but not as good.
you wont notice a difference in performance, maby a slight difference to the engine response but likely nothing, the noise will make you think you do tho lol
K-Tec relocated induction kits are a load of shite, the path the air has to take to get to the engine is far to long so it looses the engine torque and although it moves the filter to behind the grill, it also moves it to behind the radiator! so not as good as it sounds.
if you dont care about losing a tiny bit of power then go for a K&N, Pipercross or Powertec (Powertec apparently sound the best) only time you'll really notice the power loss is on a very hot day when you try to pull away from traffic lights or a junction when you've been sitting for a bit, it'll feel a bit slower because its sucking in hot air.
if you dont want to lose power and dont care about blowing a lot of money on an air filter then a Pipercross viper is probably what your looking for,