Not to rain on your parade, but you may have a difficult diving the Valient on Labor Day weekend. That wreck is outside the dive park in the middle of the moorings in Descanso harbor. On Labor Day weekend, the harbor fills up to capacity. This means not just lots of boats tied to moorings, but lots and lots of boats trying to find their mooring, loads of dingies racing around the harbor, plenty of PWCs moving about the harbor. And don't forget to add in significant quantities of alcohol. This all comes together to make diving the Valient rather dangerous on a big holiday weekend.
I would suggest to you to try it midweek in september or if you can only make it on the weekend, most weekends from Novenber through April have very little boat traffic in the outer harbor. That makes a much better dive of the Valient (especially if it is your first dive on it)
Also, don't forget to get permission from the harbor master before diving there. It is just a formality since you are diving where there may be boat traffic. (They typically deny permission to dive it from Memorial Day to Labor day on the weekends)
Good luck,
Jamie.