You can book a cab via following methods:
Online: http://www.denverairportshuttle.net
Telephone: +13037569399
Email: info@goldenwestairportshuttle.com
Yes, it's possible to pre-book a cab with Denver Airport Shuttle, please contact the company.
Denver Airport Shuttle has both regular and air-conditioned cabs, please mention your preference at the time of booking.
Please contact the company on their helpline number to make any changes.
Generally drivers will meet the passengers at the arrivals on airport pick ups but do check with the company.