Emanage Blue, it could be advantages to re-chipping. With the Emanage Ultimate using it ontop of the standard ECU, you will have no issue.
I would not recomend the F-Con, unless you have a dedicated tuner locally who can tune the F-Con, as software availability and japanese language barriers.
In this regard we are speaking of maximum/minimum +/- values over the ECM chip.
Have you looked into a full engine management system Like the
Haltech Or Motech EMS. The haltech can be equiped with a plug and play harness, making it as easy as unbolting the ecu to install. There are also base Maps for engine setups such as the SR20.
This is another more dependable option, because you will not be reliant on the base settings of the factory ecu, and have your maximum ability in tunning.