What next?
 

Well i have done intake and exhuast, what next? ECU? if so than what do you fellow first gen owners recomend for a GSL-SE?

I'm doing my exaust on my new -SE now, but I'm gonna be removing the oil pump next and switching to pre-mix. Then I'm going to do (in order) ignition, fuel system, and intake. Then on to planning my SC upgrade.
I'm gonna have to get my engine ported sometime, and I'm probably do a rebuild at the same time, which will (hopefully) be mid/late winer.

Concurrent to my engine mods I'm going to start on my front spoiler mod, my side trim mod, and when I can afford it, my paint job.

AND, I'm starting to plan my interior mods too, which will be concurrent with the engine and exerior mods. This includes my seats, new carpet, stereo, and biggest custom mod: my handbuilt dash.

Plus I gotta find time (and money) to do suspention, rims and tires at some point.

Next step - Fuel system : Fuel filter, pull the injectors and have them professionaly cleaned. I had one clogged over 13% !

Ignition upgrade, either a MSD or the Dual Leading bit over on Mazspeed which seems to be quite nice, I'm looking into that over the MSD on my next one.

But i heard that the stock ignition was good enough? what about ecu's?

The stock ignition is pretty good. I'm upgrading mine because of the future mods I have planned, although some people swear it gives them better pick up and/or gas-mileage.

I'm doing things in order to keep everything running well between upgrades.
General rule of thumb I've heard for ECU's is 3 mods=ECU upgrade.

ECU = $1000+

I run 14's in the 1/4 on a stock unmodifed ECU
There are many more things you will require before you need a true ECU upgrade.

Work on a cold air setup, and suspension if you havent already.

i dont know what your plans are as far as power and what you emmsions requirements are but why not get a big old carb. carbs on most motors are the cheapest way to get a good amount of power out of it. you cant do extensive porting either. unless you get a old 13b 4port or a turbo one and use it....