GT3582 is going to be laggy as hell it meant for 1.8ls or higher. The Miata guys use it for their BPs and make serious power ie around 350-400. If you can try to get a GT2560R those are good to atleast 275. One thing to note at around 250hp our stock conrods break. At 300hp with aftermarket conrods the stock piston breaks, so invest in those if you want to go higher then that.
Look around TurboMiata.net that can help you plan what size injectors you need.
iMHO you really should invest in Megasquirt, the stock ecu cant comprehend injector size change so you might run into problems there. The most important part of any engine build is the tune, because running too lean or too rich too long will kill a engine. Im not saying Rocketmans chip is bad or anything, but what im saying is its really only for moderate upgrades ie hybrid swaps. The Rocketchip might be sufficient for your goals, I would let Rocketman weigh in before you went straight to Megasquirt.
Oh yea make sure to port your intake manifold and exhaust manifold to match otherwise the head port doesnt do much good.