You can buy TOR's online:
http://shop.triumphmotorcycles.com/exhaust/id-A9608077/Accessory_Mufflers
for $550, or through a dealer.
Or you could get a custom exhaust like Carpenter for $1500. Then you have to tune it. Ca-ching.
If your vin is up to 574812
, your tune is highly restricted in terms of power. You can remedy that for a $20 cable and free software. If you spend the $550 on the TOR's, you'll get louder + more power and then you can unrestrict it with the $20 cable and free software.
Just remember that any mod that adds significant power requires re-tuning and you need to consider how you are going to accomplish that.