Hiya Nath,
R32 GTSt! Cool!!

is it manual, is it a coupe, what year is it? does it have the automatic spoiler and stuff on it?
I guess the first place to start in planning what mods you'll do, is in considering what you want to achieve with your new ride. Everything is relative and by modding one thing without proper planning, it can effect the next stage of development. i.e. a super low set of King Springs pretty much rule out the average Foxton 400R front spoiler...
I reckon let it breathe!
do the filters, the exhaust
Clear its mind!
Do an ECU reset as your fuel is different to that of Japan, and the car will perform better if it has a chance to relearn to your conditions.
Give it a physical!
Do a full service including oil, filter, fuel filter (their cheap enough), checkout the spark plug condition, clean the injectors - pretty much anything you would do on a customers car + anything else you can swing.
Then reset the ECU again.
Why reset ECU? Cos they have a learning computer that pretty much remaps how the car will process its fuel based on octane+oxygen content (which is different based on your region of the world), & how you drive.
The outcome is that with a high performance filter you will have a higher oxygen content in the mix, if the ECU is reset it will no longer perform to its old learned settings, instead it will relearn according to the new parameters input from the air flow meter and other sensors, and you will infact allow the car to perform to its optimum accordingly. This is true also for an increase in exhaust size and everything else that effects the burn process...
There are so many ways to go, but be sensible. Ask questions, do research, cut deals since you work at Nissan. Giving yourself time to shop around is probably the best thing you can do.
Good Luck...