the stock spoiler, (SES spoiler, the smaller one) is part of the SAP package. OR it can be specified with the larger wing.
If you're gonna just get the SAP front bumper, you might as well splurge on the kit, as just the bumper is $800.
As for two-tone, I think it would look sick, but you need to post up a side profile pic of your car, and a front pic. That way, we can have some members her photoshop it for ya, give you some ideas.
For my two-tone idea. I'd do the bumpers, the fender flares, the side skirts, all in the 2nd color. or maybe, you could go all the way up to the moldings as you said, I just dont know how clean it would look.
One key thing, if you're gonna do a red/black tu-tone, use red as the bottom color. This way, it will break up the monotony of having an all black bottom, like, the wheel wells and tires will be lost in the black paint, as will the vents on the SAP kit front bumper. Also, having black at the bottom, it will show up all the dirt from driving around in rain, or on dirt roads. I'd presonally suggest, doing a red lower, with black upper, and get some dark tint and black wheels. I'll see if I can get a pic of my car photoshopped to give you an idea.