Need help taking portraits of 9 people.. This equipement?

I will be taking a picture of a group of 9 people. Most will be singles and doubles but last shot I need is of the whole 9 people group. I have the Strobist DVD, so I'll rewatch that section where he shows group shooting!

I'll be using 5D, 24-70 at about f/4.0 ( to get everyone in focus). For lighting I have the following: 580ex II, 580ex, and 2 540ez all will be triggered via PW. I have light stands for all flashes, but only 2 shoot thru umbrellas.

Will this be enough? Will appreciate any tips and help!

Thanks!

Really? No one has take group portraits before??

I wouldn't be shooting at f4.0 if using 24-70. I assume this is typo. I would go for f8-f11 to make sure each one is in focus. You can use 2 off camera flashes with umbrellas on each side of the camera. But don't put too far from the camera. They shouldn't be pointing 45 deg. angle, that will make criss cross lighting. You can just put them staright facing the graoup of each side of the camera. This will give simple flat lighting for the group which is easier to handle. Umbrellas high up on the lightstands pointing stright at them, not down unless you want to reduce light on the bg.

Thanks Bobby.. Love your work, have been following your blog for a while now

Everything Bobby said and more:

Shoot those groups a bit loose, you can always tighten it up later in PP, better than cutting the end people off.
Take several of the group, there's always at least one person who will either be blinking, yawning, or just generally having a stupid expression on their face.
I was going to suggest exactly the same f-stop, you want some depth of field there and f/4 just ain't enough.

I'm assuming you'll be using a tripod, and if so, after you've posed the group and composed the shot to your liking in the viewfinder, look up and watch the group with your eyes instead of thru the viewfinder while you actually take the photographs. Its a lot easier to see blinks and the like that way.
Bobby's suggestions about lighting are spot on, you want the lights to be almost straight on, not at an angle to the group or you're going to get nasty shadows across the people in the back row.
Nine isn't too bad of a group, its when you get over 100 that it gets hairy.

Thanks for your tips..

Just rewatched the group part of Strobist DVD! Yes, will be using tripod, background and 4 or 5 flashes! If I do have 5 flashes with me, I'll try using one for the background/rim light..