I'm using PF nearly as original requester mentioned and perhaps in a way that Tuan didn't consider. We have dance events for which most folks just register and pay; using PF they work through payment and confirmation on sucessive screens. Multiple members of the party just use the form multiple times.
Now some people want hospitality (they want to stay in a home, not a hotel) so I just create that as a new form, which is to PF a new event in the database. Again, multiple folks = multiple usages.
Finally, some people provide hospitality, another form, another 'event'.
The beauty is that notifications emails for each event can be sent separately (different addresse) and the records may be parsed on 'event' - which I suspect is exactly what the client wants. Each event has it's own price, too.