I have bought the one step colder plugs from another source. I want to say they were something V22.
I would highly recommend against them if you live in a climate that gets snow. There is no performance benefit on an otherwise stock engine and the colder plugs foul pretty heavily, leading to rough idle and in extreme cases difficulty starting in cold weather.
With respect to intakes, the biggest difference is aesthetics. There isn't much performance to be gained from an intake as many aftermarket companies have found that the stock one is incredibly well designed. If you want more induction noise, by all means, but don't expect performance improvements.
With all modern turbo cars, the biggest improvement that you will get in performance comes from a tune. If performance is what you want, start there.
