Hi i am no expert on tuning but from what i have read over the years, this is my take on it. High performance cam shafts adjust the valve timing and the result is an increase in HP at a certain rpm usualy at high rpm for top speed, however you LOSE power at lower rpm . Cam shaft profile is only one part of the tuning process, the whole system needs to be matched together this means air flow thro the filter, back pressure of the exhaust and fuel mixture and final checking on a dyno. A mis match of any of the above can give negative results.

As a general rule the more air you can get through the engine and the exhaust the more power is available. I would go for the bigger pipes.