I would look for a fitter with good reviews. Just google their name and see if you can find positive feedback on them. Outside of that, just look for somebody who has completed some sort of formal fit training. If they've been to a training program they can fit you according to the common bike fit guidelines. IME, the computer fit stuff is usually offered on the most expensive bike fits ($300+ around here) and is really only beneficial for racers or riders looking to maximize power/efficiency. Nothing wrong with that if you can afford it, but absolutely not necessary if you just want to be comfortable and pain free.