I also use the LCE header and def recomend it the only other one I'd use is Doug Thorely's. His is supposed to be the one LCE is selling from what I'm told but have yet to see anything proving this. I used LCE's for the same reason it is a straight 4 to 1 collector which is def the proper design especialy on a 4 banger. Step down headers are (only IMO) not much better than a factory manifold yes there is a dif but not much.
As for using SC's well I've found that doing some maching to the block and head to be more productive and cheaper to do than installing a SC and be able to maintain the durability of the 3rz.
SC's are great if you're also using a stage 2 cam but must be using adjustable cam gears so you can adjust everything. Adding the fifth injector is almost a must or the piggy back as stated by BigMike Realisticly the factory cams aren't up to the task of a SC unless your using adjustable gears.(just not maximising the potential) The SC's boost should kick at the RPM range as your as your cams top range.For example if your cam is a 2500 to say 3500 your SC boost should kick at 3400 to pick up where the cam is leaving off.(this is my opinion)
