I know what you mean about headrippers - the first ever cervival adjustment I got in the student clinic at Palmer West College left me with numbness and tingling down both arms for 3 days! (I got better!)
The most important decision about choosing a chiropractor is whether or not his or her technique suits you - some people love the `twist their head until they can look backwards without a mirror' adjustments - and then to see if their personality matches yours. I've been to chiropractors who have had wonderful personalities, but they adjust like Goofy. Technique first, personality second.