First cook: 450F for 30 minutes or until brown. Then turn the oven down to 300F and cook until internal temperature is 125F.
Rest for at least an hour. Wrap in foil, then plastic wrap, then chill.
Reheat: 350F oven for about 1.5 hours until internal temp reaches 115F. Allow to rest for 15 mins.
Edit: Remove plastic wrap. Reheat in foil.
Well there are frozen souffles. Not quite the same. ;)
Anyway you will need to figure it out for your kitchen and for your workflow. Selling souffles is great for the bottom line. Coordination is really important from selling the souffle (preorder) to serving it.