First of all a 2009 Civic is Mcpherson strut so there are not any upper A-arms. I hate to sound like a broken record, but it'll be MUCH easier to get this lower if you use hydraulics vs. some kind of strut bag due to the large size of a bag, etc. I would first suggest just letting the car sit as low as it'll go naturally and my guess is you'd be surprised how low it'll sit (especially with 18's up front). From there you can decide if it's really necessary to start cutting. BTW, I drive the same bodystyle civic as a commuter car, so the suspension is very familiar to me. Check out
www.hydroholics.net. -Aaron