I would not recommend coming into a meeting with written handouts etc. In our case, the school ran the meeting and I had to work really hard to discuss the topics that were important to me. Sometimes teachers and administration can give you the best compliments about your child which made me believe that they understood my situation. Instead, they wanted to start with the positives and then tell me reasons why they wouldn't consider my request.
Bring all your data: tests, recommendations from adults in you child's life, portfolio type items (something the teachers may not know about them)and any literature you can quote with little searching.
If math is your main goal, talk about that. If you suggest subject acceleration, maybe offer a trial of a month after which everyone can have another meeting.
Get ready to answer their concerns: social issues, logistics of a grade skips or subject acceleration, how this affects learning in later grades etc. The more prepared you are to answer these questions, the faster the meeting will go in your direction.
Most important part of the meeting: conclusion. Summarize what your understanding is and see if everyone agrees. For example: "so if I understand correctly, the plan is for DC to attend Mrs. Jones' math class starting next week and we will meet again in a month to see how everything is going?". That way there is no wiggle room for other teachers to talk afterward. They should be able to discuss this in a meeting with you, not later and give you a "verdict".
Jen