I would suggest visiting GSXR sites and trying to find used parts/guys parting out their bikes. It's gonna be pretty tough to track down OEM stuff for a 13 year old bike - and even if you could order it from the factory, it'd be beyond expensive and defintely not worth it. Aftermarket headers and pipes would be lighter and would look better, not to mention give you a performance boost once the carbs are rejetted.
Suspension is something that would work from a used/parted out bike provided that the forks are straight, seals aren't leaking, etc - you might want to do some research as you may be able to put newer year forks/shocks on your bike without any modification and for a decent price would get better components.
I have a Penske shock and RaceTech front internals on my TL and love it - good luck with your search!