Family portrait of 11

My wife and her sisters have asked me to take a family portrait of the 11 of us. 7 adults, 4 kids ages 16,12,12,4.

This will be shot in my great room. I have on order 2 umbrella kits with shoot thru and reflective umbrellas, an additional flash and some radio triggers (RF-603 c3)to fire them. So my lighting will be 2 flash and umbrellas.

My questions really lie in the lighting. Is a good basic set up to start with the flashes above camera and 45deg each side?
Equal balance on flash power?
Shoot thru or bounce flash off umbrella?

Best lense i guess is going to be my kit or nifty 50. I dont think o have the room for my 70-200 indoors and have full shot.

i hope to have some time to practice before the day of the shoot.
So any and all help would be appreciated.

Thanks,
Jeff

Unless you are going to stack your subjects (kids kneeling in front, for example), you may run out of light. I find bouncing my lights off the reflective side instead of shoot thru gives me about 1 f stop more light. I'd probably start with reflective umbrellas and work from there.

Seamus, i guess that was the plan to stack um up. 4/3/4 maybe
Thanks for the tip.

only use one umbrella. Put it right at your side (as close to in line with your camera as possible) and raise it up above your head. Put both flashes in that umbrella. Fire away. It's simple, you avoid difficult shadows, and you improve efficiency of your flashes by using two.

just came across a 3rd flash so should i go with a standard key,fill,backlight setup?
tihinking of getting a dark backdrop.
thanks