One BIG thing to consider when reserving transportation is LUGGAGE. Take a look at the size of your bags, and how much stuff you think you'll be bringing. Some people travel light, but there are others that bring everything they own.
For 6 people, a standard van might not be the most glamorous, but would certainly do the job quite well, and not be very expensive at all, relatively speaking.
If you want glamour and glitz, a 10 passenger stretched limousine would also do the trick. (A 6 passenger limo might be able to squeeze the people in, but luggage space would be very tight)