I have a set of standard level carbon SIL cans on my 2002 900ssie.
Pics here:
http://flickr.com/photos/phillc/51907417/ http://flickr.com/photos/phillc/51907419/ I also used these on my previous 750ssie. They swap across no problem. Originally bought them from Nelly at Cornerspeed for a good price.
I haven't changed ECU and have a bad "cough" at 4,000 rpm. This should be fixable with correct tuning.
I would like high level cans, and believe that the hangers can be modded to keep the footpegs, but it raises the hight of the pegs and probably wouldn't be so comfortable for your passenger.
I've also taken the trumpets off the airbox and changed to a 14t front sprocket.