Panel Filter basically just improves the shift and high end feel slightly better and it is really for a slightly increase and filter economy. As for the induction kit make sure it has a cold air box which none of the current induction kit has for the IS200, since you do not want so many hot air sucking into your engine!...I would recommened a Tom's Foam filter since it is the most quality built and more value for money compare to TRD...TRD is a good filter, but you will have to change it once every 15,000 km.
Matt =)