Steve,
Since it appears you will arriving a few days early, it would be a very good time to launch and spend a few days exploring Wahweap Bay (toward Lone Rock). On the far side of Wahweap Bay (the side across from the facilities) you will find several coves that provide good anchorages yet are close enough for easy access to the marina, store and other facilities. This is not the most scenic port of Lake Powell, but would give you a good "feel" for local conditions and boatcamping or beach camping.
One of the realities of cruising Lake Powell is that once you leave your marina (Wahweap, Antelope, Bullfrog, etc), it's a long way uplake to the next developed facility. You could spend some time exploring all of Wahweap Bay, yet still be relatively close to Wahweap for rendezvous with other incoming C-Brats.
Another item you may encounter regards sleeping in your truck at Wahweap. The National Park Service has campgrounds at Wahweap but they are a half mile or so from the marina. You are largely left with the alternative of launching your boat (and staying aboard at the marina ($), or somewhere away from the developed area (free), or staying in the truck at the campground ($) prior to launch. I suspect the NPS would discourage sleeping in your truck (ie. on the launch ramp) or leaving your boat on the courtesy dock overnight.
There are some courtesy slips at the marina that you can use for a few hours (ie. time to go to the hotel for lunch, or maybe a quick trip to the full service grocery store in Page).
You can spend some pre-departure time doing some research on Powell. Check out the NPS site (
http://www.nps.gov/glca/ ) and spend some time looking at Lake Powell on GoogleEarth!
...just some thoughts; have Fun!
Best,
Casey
C-Dory Naknek
Lake Montezuma, AZ