Uhh... Power Commander's are for FI bikes... They allow you to alter the fuel curve... Since your bike is carb'd, I wouldn't worry about it...
If all you care about is the sound... Just get a slip-on... If you want lots more power, get a full system... Getting a full system will get rid of the Exup valve,(which PeterR1 keeps telling everyone and me to keep) causing you to lose power in the lower band, the performance gains up top are considerable...
Since I know you only want it for the noise... Just get a slip-on...