Things rarely happen the same way twice. Why not capture your presentation as it's happening? Use it for marketing your next speaking engagement or just for your own archive. Better yet, offer it to people who couldn't make it to hear you speak.
This service comes with several options from "bare-bones" single-camera archive style to multi-camera with audience reactions and editing. The choice is yours but I'm happy to answer your questions in advance of your event.
Note: Northwest Films does not currently specialize in weddings. There's an entire industry around those and hundreds of filmmakers far more experienced in that field.