If you are planning on putting in some other form of engine managment in the spring, save yourself the green now and just get MPI, Haltech, AEM, whatever you want in the spring. With your mods, stock plugs, and 8.5:1 CR you should be just fine on the factory ECU until the spring when you get your full engine management solution, whatever that may be.
Just make sure you have a wideband, but the mods you listed I would think you would be fine at 10psi or so on the fatory turbo.