I used a tour and transport company based in Pattaya called Khrong Fa.
Email:
khrongfa@ego.co.th
The name of the contact I dealt with was Ms Arunee. She will respond in English.
Driver was waiting for me at arrival gate at BKK Airport to take me to Pattaya. Car was a 10yr old sedan with aircon. Nothing flash about it, but who cares?
The fare was 1050 Baht including all tolls. I still have the receipt!