Prepare yourself for a lot of CAI all the way as SRI sucks up a million degree air. My personal opinion, SRI is good as it's a short smooth tube which gives very little resistance allowing more air flow. I doubt the resistance between a stock filter and a drop in is enough to gain more than 1-2 hp.
RainMaker posted a dyno comparison, so far the stock airbox and stock paper filter made the best power. Ever so slight power loss with a foam panel filter. And a noticable loss of midrange power with an Injen CAI.
Buy an intake for noise if you want, do not delude yourself into thinking it buys you any horsepower. Look at the pipe going from the airbox to the turbo inlet and you will see why the stock airbox is good enough. I freely admit that the K&N Typhoon on my car is only there for sound. I took it off for a while to see if I noticed any more power with the stock airbox (answer: no), but finally gave in to tempation and put it back on so I could hear the noise clearly again... LOL
I am with scubadiver424...SPT SR stole my low-end, and you have to start somewhere...and while it sounded pretty cool...made the car weak down low and just wasn't worth any high end gains I MAY have had.