Let's keep this train off the tracks for one more minute.
You should take a step back and reread Frank's thread... unless you have buckets of money to burn, as Frank has undoubtedly done by this point, it might pay to stick a little closer to the script. The engine bay in this car and the drivetrain location are very unlike the other cars you mention. I've put big engines in small cars before.. and the recipe has always been the same, pull the engine, bang here, dent there, extend the steering joints, weld up a crossmember add a little tunnel sheet metal and voila, success. The 818 is a different animal, it doesn't particularly lend itself to reengineering there is no big old engine bay, you are tucking a uniquely shaped engine into a uniquely shaped spiderweb of tubes and braces. Even FFR has still not put their long awaited, long promised eco boost option into production. If they cant get a second powertrain going in what... 2 years now? Then you have a long road ahead of you. I'm not knocking your ambition, skill, or budget I'm just saying think it all out before you plink down the money for the kit if you don't like the ej powertrain. I think Frank would agree with me on these points.
If you are really looking for something different, I still think a supercharged fa20 would be stellar in this car. It would still take some work, and maybe one of your adapter plates, but it works dimensionally. Combine that with the fact that several of the supercharger kits on the market come with a2w intercoolers and it's an even better fit for the 818. You can even start NA and add the boost later.
Good luck whatever you end up doing.