$60-$90 an hour.
You can install all of the things mentioned... with relative ease, if you are the least bit mechanically inclined...
one thing can deter you from installation. 1) a proper place to do it. 2) the proper tools.
if you don't have and don't want to purchase jackstands and/or a floor jack... then paying someone will be much easier.
Also springs need a spring compressor... one can be found for $15-$20 if you look at the right places, or you can borrow one from Autozone for a $40 deposit.