To leave about 1-1.25" of rake you'll want to set your Bilsteins at 0 when you install the lift.
In order to run 35x12.5 tires on your stock wheels you're going to need spacers. Typically 1/4" spacers are enough but it depends on the tire and the truck.... Toyo MT's and Nitto Trail Grapplers for example actually measure 13.4" wide when mounted.
Who did you get the quote for the lift from? I'm not very familiar with Zone lift pricing but if you haven't talked to the guys at Bully's Performance I would highly recommend that you do. Just let them know what you want and that you're a forum member and they'll hook you up with great pricing. Send them an email at email@example.com