Welcome to the forum. Have a look through the exhaust section - everything you want to know (and more) will be found there. It's not possible to fit a slip on end can to the XSR - you'll be looking at a whole system, so start saving!
I've moved this query to the exhaust discussion.
I like the Akrapovic full system I installed a lot. It's only very slightly louder, and at a slightly lower frequency. I can't argue with the posts that point out that aftermarket systems are high cost/low reward propositions with this bike. I might not do it again if I had it to do over. I installed Ohlins cartridges and an Ohlins shock with a spring to match my weight, and that has been a far better value proposition. With good tires inflated properly and a decent spring set-up this bike is just a blast to ride- damn near perfect for just enjoying the road and the sheer pleasure of riding.
There is a slip fit made for the MT, so it will fit the XSR. Problem is you do cut the stock system to slip it on the head pipes.
Personally I bought a Delkevic full 18" stainless can exhaust to get better tone without much increase in volume and the looks. I contacted them to make sure I didn't need a reflash, they said no need. I also didn't plan on any performance gain. The exhaust was everything I expected, great tone with only a few decibels louder sound. I got a reading of 87 dB at a 45° angle and about 24" away from the tip. I run the quiet core included with the exhaust, but also got the "quieter core" in the event it was too loud. Now it just has the perfect tone for me to enjoy it without irritating everyone within 20 feet of me.