I'm up for a promotion, have to give 15 min presentation about random subject.

I'm up for a promotion, have to give 15 min presentation about random subject. I will have 30 min to prepare for this 15 min presentation. I have no idea what the subject will be. They already know I have a stutter, but in the first interview I managed to keep cool, and beside a few stutters I spoke quite fluidly. Any recommendations or helpfull tips ? What I find most difficult is focussing on slow speech and at the same time keeping eye contact and interact with the listeners.... and all that shit that you do to nail a presentation. Should I try to focus on one of those things ? so basicly fluidly v interaction... thnx EDIT: nailed it !