Okay, I got the car up on jacks. Here's the rundown on the mods:
Full 3" turbo back exhaust
tokico illumina adjustable shocks and eibach springs
STOCK turbo with internal wastegate. Manual Boost Control in car.
Greddy Type S
Autotech Sport Comp boost and a/f gauges - regular O2 sensor
Injen CAI
Baer Big Brake Kit

Questions:
1. Is there any way to figure out what injectors are in the car without pulling them?
2. Would the computer be left stock, or do you guys run piggyback systems a lot.
For both of these questions, the A/F meter remains in the green under full throttle, even at 17 or 18 lbs of boost. I did turn it down to around 15.

3. I'm not really looking to increase performance, just make it quieter and reliable. For the reliability part, would a wideband o2 sensor be the first choice, to make sure that I'm not leaning out under boost? I'm also thinking water injection.

Any and all suggestions are appreciated. I'm used to German and Swedish cars, and have no experience with anything Japanese.

Water Injection FTW!

Ummm....If it still has a 14b, then I'd say its prolly the stock ecu as well. And if you want reliability and good gas mileage, turn the boost waaaaaay down. I drive around town at 10 psi, then when I wanna gas it, switch my boost controller and it jumps to 18.

Reliability and performance don't go hand and hand. the 2 Generation don't have 14B they have the t25 (T two small).

Injectors are 450cc. just from reading your mod list you car is pretty much stock. what are you goals for it ????

Honestly, I can say this thing is quick, much quicker thank a stock GSX. That being said, I have no experience modifying these cars (only selling them in a previous life). I am perfectly happy with the performance, I just want to make sure that I'm not going to blow it up. Right now I'm running it at 15psi. Water injection is more of a fun diversion for me. I've been looking into it for my Saab for awhile. That's the only other turbo car I've owned, and one of my least modified cars. I just like the concept.

You can have reliability and performance. just do everything right. You can have 600whp and reliability, but I'd say 300-350whp is doable without compromising your dailydriver.

I goofed, you are correct on the t25