the best is to shoot outdoor without flash since you only have a sb-800. sicne you mentioned executives, do take note of how much time they are giving you. most top ppl wan it to be done asap and expect you to produce results. if result no good, like what others said, you just killed your own name as a photographer. if really bo pian have to shoot,
1. know who is coming, who is suppose to sit where (dont ask the company director to stand at the corner just becos he shortest!)
2. what time and where you can shoot and what kind of light you will get. outdoor possible?
most importantly, since it seem like you are doing this big group e first time....let them know what are your capabilities,limitations. dont let them have high hopes to expect photo to be like those in annual magazines etc( generally shot w 2 or 3 studio lights on location) compared to what you did ( w a SB800).