3sgte turbo upgrade which to get Options

[mk7celica]

Hello, I am kinda new here. I have a 1994 celica with a 3sgte swap with no engine mods but have a 3 inch dp and full 3 inch exhaust and a fcd, 4 inck air filter with custom air intake pipe and ebay special fmic. What I want to do is upgrade my turbo from the ct26. Dont want a ct27 or rebuild upgrade < figure I will want to upgrade again with these>Can I use any turbo I pick to my liking and bolt to my manifold with a adaptor or get a new manifold as long as I have A external wastegate and the down pipe that bolts to the turbo and exhaust. what I mean is if I have a turbo, wastegate and proper fittment to my manifold it will work? And also Do I have to have a ems to run right with the new turbo,I read that the ecu cuts out at 275 hp is that to the wheels or crank and is it the same for a jdm engine. Also ?i have some bigger injectors on my list to get is this a must with a new turbo?

[mk7celica]

SoDo you think If I get a rebuilt upgrade ct26 similir to the ct27 but bigger. The one I am looking at is a 54 trim garret housing .80A/R exhaust .63A/R to4e and ats rom tune cause I think they can tune a upgraded ct26 550 injectors and fuel rail I can DO 300-325hp? alreadt have walbro pump