Ahh... then you're doing this for a friend. As I said, that's completely different, no pressure you're not a hired gun getting paid for professional quality work. You should have stated that first. It appeared as you were doing a job. That means something completely different to professional wedding/event photographers.
BTW... two pro-quality strobes will be far less to move around than 5 speedlites on stands with modifiers, triggers, etc. And you don't have to rent Elinchroms, any quality hp strobe will suffice.
I'll look into the strobes. Any ideas on lighting set ups? I'm thinking indoors will be far easier to control as outdoors I'll end up limited by the sync speed. And stopping down would just reduce the power of the flash further. Indoors in a meeting room I could bounce the flash off walls or ceiling for smaller groups of 8. And the ID shots I will use umbrella high and camera right with a reflector or second umbrella underneath for fill. It's really the group shot of 30 that troubles me. Might just shoot that outside and hope the sun f---s off behind a cloud! If not - shade. I scouted the entrance and it's sort of shaded by trees to an extent. Flash would be useless with that many people outdoors, right? Or just fire all 5 into the crowd and hope to God that some photons land on a few faces!