if you just put slip ons you wouldn't need a tune. That being said, your bike would probably benefit with a tune and an air cleaner. They are fairly leaned out from the factory - a tune will add more fuel, better throttle response, run cooler... etc.
Not sure of the year of your bike but if it has a catalytic converter in the head pipe...gut it...get rid of it. Cat free head pipes can be purchased rather cheaply here on the forum or eBay, etc. Makes a significant difference in sound and the bonus feature of getting rid of a lot of that heat on the right side as well.
Check out American Custom Exhaust. www.americancustom.com/products.html Had mine pipes modified by them. Turnaround was about 7 days for your mufflers to be modified. They do excellent work and you have a choice of no baffles, quiet baffles, or mid-rumble baffles. I have the mid-rumble and can still listen to the radio or sit in the saddle all day without the noise bothering me.