Ringflash and 52 Inch Moon Unit for Groups

I asked this a few months ago but got no reply. I need to shoot large groups (~ 35 people) in a church with a high celiing. At present I am using a Canon 550EX with a Milagrid diffuser which works but it is at the limit of what it can do. More power would be good. Has anyone used an Alienbees or similar ringflash with a large moon unit, putting the camera lens through the center of the ringflash with the moon unit mounted?

I gather that ringflashes without a moon unit produce circular catchlights in the eyes and require a great deal of retouching. I am hoping that the ringlash+moon unit combination reduces the need for retouching and that some sort of baffle can be used in the moon unit to avoid the circular catchlights.

Has anyone tried this? Does it work?