You can get away without a reflash if you do one upgrade, either intake or exhaust, but if you do both, you need to get a reflash done.
Are you running the SE backplate, or stock?
I would recommend the SE backplate if you plan on doing exhaust and other mods.
See this thread for a list of parts for the SE kit.
Got a SE air filter? Thinking about going to the SE air filter setup?
You can order the parts individually cheaper than if you bought the "kit".
Also, I would recommend the Zipper's air filter if you want more airflow. The Zipper's filter is 1/2" taller than the stock/SE/K&N. PN#1011-0782 thru Drag Specialties dealers. But you need the SE backplate to run it.