Multiple recipients, not dropdown, but selectable

Hi,

I would like to create a form where visitors to my website can choose the recipient. However, this is not easily solved by pipes. I have a number of choices I want to give to address the email.
The sender can either:
– select one of 15 groups
– select one of 150 individual recipients
– select one of 12 parties

The 150 individuals are all part of both the 12 as well as the 15 groups, but not spread evenly.

Any suggestions on how to do this are very welcome.

http://wordpress.org/extend/plugins/contact-form-7/