If by next weekend, you mean THIS weekend, it may be too late (plus you didn't ask for route info) but, I'm not a big fan of the Flagstaff to GC route; I prefer out I-40 to Williams and then north. Of course taking one route up and another back would add some variety (I particularly do not like the Flagstaff route at night). Williams has the Grand Canyon Railroad which is a nice stop (if you have time). Beautiful weather this weekend.

If you are already in Sedona, my favorite sandwich shop is Memories. If you have a way to keep it fresh you could just pick up a sandwich from there!!