I live about 3 hours outside Moab Utah where the park is located. I've been there a number of times and I'll tell you that it's going to be hot as hell there. Probably near 110 and dry as a bone, your kit lens will be fine, just get a few filters circular polarizer being the most important in my opinion.
More important than camera gear will be bringing along a way to keep yourself cool, and plenty of water. I'd get a brimmed hat, one of those scarves that you soak in water and wrap about your neck, sunglasses, sturdy shoes, and a camelback style hydration pack. You'll be glad you did, trust me!
You won't have to make too many tough hikes to get into most of the arches and scenery you've seen on postcards etc. Delicate arch takes about 20 minutes and none of it is difficult, others are about the same or easier.
Have fun and post some of the shots when you get back.
SLC