You may want new spring isolators too. Definately get the strut mounts, it adds to the cost, but you'll regret it later you didn't do it. If you can't afford them all, do the fronts at least; they take the most punishment. I have 1 rear isolator brand new from GM left over from my spring/strut upgrade (didn't come in-time, and couldn't return) if you want it.
BTW: Not sure if I would reccommend the KYB's and Eibach combo. The KYB's aren't that much stiffer than stock. I'm still kicking myself for not getting the GMPP springs, people seem to be happy with them and the KYB's.