From what I've heard on the forum any shop like Auto Zone, Advanced, Pep Boys etc should be able to rent you the spring compressor. Wouldn't be a bad idea to make a few calls first just to make sure though.
Yup, $110 each for the Bilsteins sounds about right. Contact either Andrew or Jeremiah at Bully's Performance. They'll hook you up with the best pricing on them, just be sure to mention that you're a forum member.
With a 2.5" leveling kit you can fit 35x12.5 tires. But to put them on your stock wheels you will need spacers in order to clear the upper A-arm.
Yes, what you're describing sounds like a skid plate. I would definitely leave it on there. As long as you're going straight over curbs or bumps (with both tires going over them as well) the skid plate clearance shouldn't be a problem. And if it is you're just better off smashing that skid plate against something than your front diff.