Take a look at this:
Impala SS Bilstein BMR ZZ GXP Suspension Upgrades Done! - LS1TECH
Only things I would consider "bad" (not really but I figure there are better parts)
-ZZP LCA's (as he demonstrated in the thread quality control maybe an issue (different Balljoints and the front mount adjustment), its nice to have adjustable Front LCA's so that is a huge advantage); Our front mounts are rubber and there is no replacement, a solid mount is really what we should have here, only 2 LCA's come that way: Ron Vogel LCA's (which there about 10 sets in existence) and ZZP LCA's.
-Front brakes I would have gone CTS-V but that is just me
-Front sway bar could have been upgraded to a thicker Sway; GMPP or what have you, but GXPs may have a nice front sway already.
-An extra (and expensive step) would be to valve the Struts perfectly to the Progressive rate of the Eibachs. Eibachs are known to be stiff, but I imagine those Bilsteins adapt to the Springs just fine, so my point may be null here. Coilovers are the other option here; but those aren't perfect either.
This is a good build up kiddies.
**CREDIT TO TLSHEFF FOR FINDING THIS**