Had neck pain for over a year now and I want ultrasound. Where should I go?

Spine specialist. Significant neck pain of a year's duration is certainly abnormal. It can be caused from arthritic conditions, though ruling out other, more serious conditions would be in order. You would best be served by seeing a spine specialist so that a good history and physical exam can be performed. X-ray and MRI imaging are usually more helpful for diagnosis than ultrasound.