I think the main problem here is that you already went out and pretty much bought a full suspension, and THEN asked what was the best setup. The logical thing would be do ask BEFORE you buy the parts. A lot of info can be found by searching, and when it comes down to it, the best suspension setup depends directly on your personal preferences and what you want to do with the car (yes, this has been said several times in this thread already). The BAT 21mm rear sway bar is GREAT, depending on your application. But we can't really help you without knowing exactly what you want, intend, and prefer.
Bottom line: you already bought new suspension components, and then ask what you should do...expect to get some crap about that, its not a very logical procedure