If you need the kit I'd recommend getting it sooner than later. I ordered the kit early April, and am just receiving it today. It seems to be an item the doesn't stay on the shelf for very long. This was the second item I ordered from flyin miata that was on back order and took more than two months to receive.
The kit makes the swap stoopid simple to do. Like most of FM's products, it's well put together and works exactly as advertised. Now if they would make an intake that adapts everything nicely as well, that would be awesome. The ECU works just like normal. With the larger injectors from the 1.8, it works just like it's supposed to. You could swap ECU's but you would have to do some repinning and wiring work, and it isn't necessary.