Price will vary by market.

You need to change the vtec engaugement point, and raise the redline to 8500 rpm. The difference in fuel consumption is minimal. I would get a S2 or similar Intake Manifold. Not sure how CA inspection works, but i hear that its harsh.

Personally, I would run the OEM GSR ecu over the S2 until you get it on the dyno. Over-Rev could cause premature bearing failure, etc.