How long have you been making pizza?
Have you ever done it professionally?
When you make pizza, how many do you normally bake at a time?
Are you comfortable using a peel?
What style pizza are you planning on serving?
Pre-baking is the kiss of death for good pizza, but if you lack the experience and can't stretch a skin and top it quickly, then you might not have any choice.
Will there be much other food or is pizza the primary focus of the party?
Are people all arriving at once or will the party be spread out over a few hours?
What time is the party starting?
What is your oven's peak temp? Inner dimensions? BTU output? Stone material and thickness?
If you've got hungry guests and not a lot of other food to offer and have to get out 100 pizzas quickly, then not only do you have to be able to make them quickly, but the oven has to be able to bake them quickly as well. If the oven is weak and/or doesn't have a lot of thermal mass, then you might be forced into par-baking- even if you do have the stretching skills.