FMIC or no FMIC?

I am finally getting serious about my car so I would like a few thoughts on adding a FMIC right now, or waiting. I have a '99 eclipse GSX with a few slight mods to it: evo III 16g turbo, ACT 2600 clutch, blow off valve, exhaust, little things like that. I just bought 550 cc injectors that will go on it along with a new fuel pump and an SAFC.

So here is my real questions, do I really need an FMIC right away? I would eventually like to make about 300 but I know with the few mods I have with out a core I will not make that on pump. I have all the piping for a FMIC I just need the core, however, I do not have the money right now for one and realistically I probable would not have the money until next spring. If I don't get a core all I need to buy is a fuel pump and then I can tune, so potentially it could be ready to tune in a few short weeks.

So my questions are how much would people guess I can make with and with out the FMIC and if I would be better off waiting to tune until next spring or if I should tune now and at least have a little fun with the car. I am getting the itch to do something to it now, but it people really think tuning with out a core is a waist and I' better off waiting until it can add it all at once I will. I know I ill eventually add a core because then I can run more boost and add a few more mods, I just can’t decide if its worth tuning now or not.