You can book a taxi via following methods:
Online: http://cirehire-wiltshire.co.uk/
Telephone: +44 124 981 2271
Yes, it's possible to pre-book a taxi with Cire Hire, please contact the company.
Cire Hire has both regular and air-conditioned taxis, 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.