okay.
here's a run-down of my car and installed parts:

88 FC Tii
cone air-filter
aftermarket BOV
aftermarket downpipe
DIY FCD
highflow catalytic convertor
aftermarket cat-back exhaust
manual boost controller
rim+tire combo
strut+spring combo

other than the mods i listed...my car is entirely stock.
the car runs OK, except sometimes it bogs out under boost. i currently have it set to 10psi.
now i want to take care of the ECU upgrade. i'm most likely looking to go with an E-Manage (as this car is my daily driver, and i am not a professional race car driver) because it is the most economical way, with room too expand.
oh yes, i'm looking to upgrade my secondary injectors to 720cc also.

i can't find any good solid information on the E-Manage online...so what can it do? does anyone with an RX-7 on this forum use an E-manage?

i've also heard that you can only plug in ONE(1) optional harness...is that true? or can i buy all the harnesses and hook 'em all up to make it work like (cheap alternative to) a stand-alone ECU?

any input would be appreciated. thanks.