Save yourself alot of wasted money. Paying for a dyno with a simple exhaust change is an utter and complete waste of $. Get a Powervision, get a custom map that comes free with it, autotune using the Powervision and there's not a single chance that any professional tuner will tune the stock motor any better. PERIOD. http://www.fuelmotousa.com/site/power-vision.html
After more than 10 years of efi tuning, at least a half dozen professional dyno tunes on various bikes, extensive experience with SEPST tuner and extensive experience tuning my 110 with the Powervision, I can assure you there's no tuner on the market that can tune a bike across the entire rpm and KPa range using the stock 02 sensors other than the DynoJet Powervision. The OP is looking for a simple and economical way to tune a simple exhaust change with a CAT removed.
Those suggesting he should pay for a professional dynotune are unfortunately providing very poor advice. There's simply no professional tune that will perform any better on an almost completely stock bike than a solid custom map combined with the PowerVision autotuning capability.