I put some KYB's on the back of my Element a few months ago. Borrowed spring compressors, no alignment needed. Probably took me a good 4 hours total time, I have previous auto repair experience.
FYI on parts purchase. I shop online a lot at Advance Auto parts website. Log in/create an account for email specials. I typically get a 20% off email, and see a 20% off web bought parts banner when shopping. Research and buy online, pick up at your local store. Saves me quite a bit of cash.