Use the JDM ITR ecu.

Try to get a OBD-2B ecu so you don't have to use a jumper harness.

You'll need the two post mounting bracket from the Si on the timing belt side. Integras use 3-post mounts.

You'll need to change the plug on the IAT sensor and convert it for use on the intake manifold instead of on the intake piping like the USDM B16 uses.

Other than that, it's fairly easy to swap. I'm sure I'm forgetting something.