I would suggest that the OP give various car services a call, or email, to see what they have to offer in the way of transportation for 9, as well as all their baggage. I know that we used TT back in '01, and had booked a van because we had 6 people. They showed up in a stretch limo, same fee, but we had a bag or two in the car with us. I think we had a total of 9 bags between the 6 of us...one family was a very heavy packer!!
Give the companies a call/email and see what they can do for you. Let us know how it works out, as I'm sure others have the same situation.