Vertical, this might help:
Also do a search for '900RR header' on the forums, you'll get LOTS of info.
My 900RR header was a '97, and it did not have that bracket on the end. Check with MarylandMike as he had the same as you and chopped it off and went the slip-on, rather than bolt-on route.
Although you can get the bolt-on can, it just doesn't look as clean to me.
Look at the pics on mine, you can see how clean it can be without that bolt-bracket doo-hickey in the way. I absolutely love this setup, really cleans up the tail, IMO.
Check the diameter of your pipe if you cut it off. Mine was 61mm and required a 63 mm slip-on (there was quite a bit of slack, but when you crank down on the clamp, she tightens up nicely; I didn't put any gasket or sealer on there, either).
You can also get the shorter GP can style like I did, or get a Black Dragon can (check youtube, just search 919 900rr black dragon, awesome vids there) and there are some Chinese carbon fiber knock-offs that you can get for pretty cheap that actually sound pretty good.
Pretty much any exhaust can, with 63mm inlet and built for liter bikes will do you. Double check your measurements, though, don't buy on my word.
It helps IMMENSELY, to have a Power Commander, though. Without the proper map, your bike can and probably will run like crap after such a drastic change to the exhaust. Less restriction, you might get more popping on deceleration, etc. If you haven't done flapper mod and removed PAIR valve, do that while doing this mod as well, that will help a bit.
Hope that helps.