I was best man at wedding and had to give a speech infront of 400 guests
I was bricking it for weeks but it went ever so well
Guests coming up to me at the bar afterwards congratulating me
My advice would be one main story with a great punchline - everyone was weak with laughter and a few spin off shorter stories that tie into the main joke
I also started by bringing a duffel bag from under the table from which I brought out props and placed them infront of me after showing each one to the room
The props had everyone guessing plus they all meant something to each story which helps you keep your train of thought

Good luck Bob