Need advice on leveling kit

Hi so im interested in putting some 285/65/18 nitto terra grapplers on some new rims. Im currently looking at the Rancho leveling kit: http://www.gorancho.com/shock_looku...verado+1500+Pickup&drive=4WD&height=&x=53&y=4. [HR][/HR]I like this kit because im not making any alterations to the truck compared to some where you have to cut in spacers and add tension to the truck. does anyone have experience with this kit? after adding it what size rims and tires could you fit? If anyone has any other kits they like im open to suggestions. also if anyone happens to know what rims I would need with backspacing as well. can I use 18*8 or 18*9 and would I need some back spacing on either?