JFK to Manhattan Transport

Hello everyone,
We will be going to New York City soon, and one thing yet to sort out is transport from the airport (JFK) to the hotel (Hyatt next to grand central station) and back again. We tried super shuttle last year, but had a bad experience and don't fancy the AirTrain/ Subway, as it's six of us plus lots of luggage. We would need two yellow cabs, so really I'm after a pre-bookable car service can anyone recommend a good one?
Thanks very much
We will be going to New York City soon, and one thing yet to sort out is transport from the airport (JFK) to the hotel (Hyatt next to grand central station) and back again. We tried super shuttle last year, but had a bad experience and don't fancy the AirTrain/ Subway, as it's six of us plus lots of luggage. We would need two yellow cabs, so really I'm after a pre-bookable car service can anyone recommend a good one?
Thanks very much