Shuttle/Taxi service

We'll need a shuttle and/or taxi service to transport our guests from our hotel to the wedding and back again.

The hotel and wedding site are located literally 2 miles from each other in Great Neck, NY. We expect that approx. 30+ guests will need transportation.

Please tell me (1) what size shuttle you think we should get; (2) how you charge - hourly, per trip, etc.; (3) whether it would be cost effective to get one shuttle to make numerous trips back and forth.

Thanks,
Amy