I find that canti brakes are the worst culprit for squealing. Chances are any of the brake pads will squeal. I would recommend getting the pad that koolstop says is best for your riding conditions. Salmon for rain, dual compound for all year (varying conditions), and black for dry weather. Then you can mess with the squeal. As far as braking power any of these pads should be adequate. The salmon will be stickier and wear faster, the black will last the longest, but the difference is marginal in my experience. One last thing you could try to fix the squeal is to grease your canti studs. Sometimes the squeal comes from excessive vibration of the brake arm that resonates through the fork (like rdtompki said) and greasing the canti stud will help in many situations where toeing isn't doing the job.