You'll notice a difference with the rear sway bar for sure. Do you need it? Honestly that's up to you. Try to find someone in your area who has one to try their car out and decide for yourself.
Re:
stock shocks/bar shifting........not sure one this one but it might hit.
There are various members here with the Saner collars.
Read this WHOLE thread to see some more pictures.
where can i get a collar for my sway bar