Im sorry but if you buy it your wasting your money.
The Factory ECU will engage VTEC at 4,800rpm under full throttle anyway.
And a redline of 8,900rpm is useless unless you have some cams that will make power that high.
The factory cams stop making usefull power at about 8,200rpm which just happens to be when the limiter cuts in. (there is a good reason its there).
If you spend the money on a set of Civic or Integra Type-R cams then being able to rev to 8,900 would be usefull, and buying the spoon controller is a good idea.
It should fit striaght into your existing harness.