the itr manifold is the same with ek9..
I don't think it is, I have the ITR one and it's a longer and fatter. Air temp sensor is different position you need to blank the hole on the 4th runner.
A skunk intake and skunk TB, will give you slightly more power but due to the extra diameter bore of the intake manifold affecting back pressure, you will be down on torque compared to an OEM intake manifold.