The ABS tends to get in the way of stuff on the ROadster.. might need the aftermarket Roadster stuff. BUT if I were you, I'd go for Brutes from Carpenter & get the best power possible.( assuming you want more power from stock bike)
AFAIK the mounting system on "T"s is very different. Either make a slip on using off the shelf parts or look at Zard. The Zards you can slip the db killer in and it's €-legal and your ears wont bleed.