Is there any good way to implement a advanced form in WP?

Hey everyone!

I got a project coming up that might need a little advanced form. Well basically its a contact form but you need to retrieve upcoming seminars from a database. In other words I need to get information about a seminar into the contact form, probably via into a checkbox list or dropdown.

It needs to be easy for the user, so he can easily create seminars and see the people who have signed up to be at the seminar(their contact info etc). Per seminar it might be up to 50-150 people signing up. So it needs to be presented in a good way.

I am unsure if a basic contact form plugin can do this, I might need to take a plugin and edit it. But I still wanted to ask if there is any good plugin able to do this? Or do I need to code it myself? If I do, do anyone of you guys have any tips for me?

Would totally appreciate it for any tips at all!