http://k5ehx.net/repeaters/qrepeater.php
...is a great resource for finding repeaters along the way.
If you have a smartphone, the ARRL Repeater Directory is available for Android - it's beta release is free, the full app will be out in Sept.
You've already got the majority of the available repeaters that work up there with the exception of:
The Bill Williams Radio Club maintains a repeater that should be accessible from the north rim. K7NAZ 146.780, no PL, and it's also part of the IRLP system node #3178. IRLP opens up the opportunity for you to link back to your home turf while here. I have a post on IRLP in the stickies on top of comms section.
The big repeaters on Mt Elden that link to most of AZ are out of range on the south side of the San Fransisco Peaks. However, you may be able to get into the Greens Peak Repeater from the 4 corners area. It's part of the Arizona Repeater Assoc Rim Link (
http://www.w7ara.org/Web/) system that covers a huge chunk of AZ. It's at 146.720 - PL 162.2, and sits at over 10,000' with great exposure to the north. I've used it from Flagstaff to Gallup, and it should reach almost to the UT border. The output has been reduced to 20W - I haven't used it since that happened so coverage may be reduced somewhat.
Enjoy the trip!
Mark - KE7IXX