We always stay at the Hyatt inside the airport. Especially with little ones, we can't beat the convenience and eating/entertainment options! The Hyatt is more expensive than going on priceline and getting one of the hotels that offers a free shuttle, but it's worth it to us!
With the number of people in your party I would recommend a towncar. If you go on the Transportation board you'll find many reviews. Happy Limo, Tiffany, Cartier, Fl Towncars are just some off the top of my head.
Hope this helps! Happy planning!!