Hey man. If you put the Big Sucker kit on, you will need a tuner... More air going in means lean conditions if you do not add fuel to the mix...
That said, I think I can save you some money. I too bought a used Vegas - mine has the Big Sucker kit and straight pipes on it, and it ran like crap - hiccuping and popping badly on decel, stumbling at constant idle. I went out and got a Wiseco fuel tuner - $177 shipped to my front door by Amazon. Installed easily and cured the issues I was having.
Why pay $340+ for the Power Commander, plus another $200+ for the dyno run?
2003 Vegas - straight pipes, Big Sucker air filter kit, black powder coated everything - foot controls, handlebars, clutch and brake housing, fork lowers, luggage rack, wheels, digital speedo with powder coated housing. Relocated key switch, red plug wires. Mustang solo seat. LED ring blinkers in front. Black DEI pipe wrap.