You need their strut spacer from their 6" kit. Not a 2" spacer stacked on top of the 4" spacer you have which is what you stated in your first post... Then yes, in the back you need everything they listed. I'd recommend getting the full 5" rear coils rather than runnign a spacer. It's a better way of lifting and rear coil spacers are known to clunk over bumps.
With the 6" lift and Bilsteins at 2.1" you're still going to rub with 37's because of the width and offset of your wheel as I stated above. You'll need to trim a bit of plastic off the back of the inner fender and possibly the front bumper valance as well. Nothing major and very easy to do. If done right most people won't even notice that anything's been trimmed.