Well, since I've been doing this a while, I pieced my stuff together. I don't believe that the other parts of the full kit are worth the convenience if you've already got or can readily buy it. Here's what I would recommend having in your basic "kit" assuming your car is relatively swirl/scratch free.
Mother's Claybar (easily sourced locally when needed)
Meg's Gold Class Wash (available in just about any car dept)
Some type of Swirl Mark Remover (I prefer Meg's DACP)
S100 Carnuba (Sourced from local Harley Davidson Dealership)
Lots of Foam Applicator Pads
Lots of Microfiber Towels for product Removal
If you feel the need to do minimal swirl mark coverup, Z5's not bad, but it's not a miracle product - it only minimizes the lightest of swirls, but allows you to cover instead of having to polish minor swirls. It uses the same ZFX and is totally compatable with Z2 where some other products aren't.
For swirls and scratches, I'd advise getting a PC with a full assortment of pads. If the car is majorly scratched/swirled, 3M FI2 is a good product. Then there's all the trim detailing stuff - I personally prefer Aerospace 303 for all the rubber (light gloss and shine, but adds UV protection). I'd also say get some Gummipfleg for the rubber seals around the doors/trunk/hood.