Now ECU is MUST because this 1NR-FE is Japani engine (that comes in many corolla JDMs).
There are only few engines who have same mountings and can seat well. Otherwise amendment need to be made for sure and same can be expected in your case too.
For Gear, wait for some other experts advise before swapping. Because its very technical from my point of view. Relation between Engine & Gear has to be very very proportional.