I'm about to lower my Eb Fairmont myself and have just purchased King Spring Lows as i did'nt want to go too low, but wanted improved handling, ride and looks. I asked my mechanic the same questions just today and his recommendations were to replace the shocks with the proper shorter units for the type of springs used as the originals are too long, and won't be working in the right areas when the suspension is under load.
He recommended Monroe GT Gas, (which i've now got) as it's not a race car, they're a reputable brand, and the price price very reasonable. It's also a good idea to change shocks with the springs as they're probly goin to give up not long after the springs go in, especially with super lows. Also...! you will need camber AND castor adjuster kits fitted as the geometry of the steeering will be drastically changed, therfore the kits will allow the front wheels to be aligned properly.....I have'nt got mine in yet but am keen to see the diff, will hopefully find out ova the weekend......