I would say about 1-1.25" would be a solid drop to maintain looks, handling, and driving comfort. My client does a very similar drive to yours. He drives to LA and spends a lot of time in the the Valley tearing through the canyons. He's gone through many different ride heights and has recently added camber plates and wheels. His current drop is about 1.4" from stock ride height. (Image attached below of his car at 1.2" on V3 before camber plates).
DSC03837 by
Justin Shih, on Flickr
DSC03834 by
Justin Shih, on Flickr
DSC03831 by
Justin Shih, on Flickr