The factory ECU (JDM/USDM/EU) has the immobilizer in it and I have not seen anyone be able to shut it off even Ecutek in the UK (they can do EJ ecu immobilizer defeats). You would need the entire harness, immobilizer module, cluster, ecu and keys from your donor car.
The Link G4+Fury can operate the electronic throttle, AVCS, and AVLS systems and they have existing base maps to get you going quickly. It also has dual knock channels as the EZ30 runs dual knock sensors.
If you need all the engine connectors contact
www.iwireservices.com they can set you up.
The 6mt is about 3-4" taller than the 5mt, it also weighs nearly 75lbs more and eats up about 10% more in drivetrain losses (that may be reduced in a fwd config.)
You can get the conversion kit from Factory Five Racing as they are starting to use them in the 818 kit cars. They provide the cable shifter levers also.
https://www.factoryfive.com/wp-content/uplo...-Conversion.pdfor Subarugears
http://www.subarugears.com/Pricing/Pricing.htmlFor the money you can do a 5 speed with a good gear set like Albins and save your self a lot of issues and weight.
The 5mt also gives you a 3:90, 4:11, and 4:44 final drive options.
The 6mt only has 3:90 unless you can find an ultra rare 4:44 RA Gravel box.
The one advantage the 6mt has is it comes with a torsen style front LSD which is nice, but you can add the same to the 5mt or if you find an GC8 RA 5mt it will already have it.
Hope that helps.