MAC, Jardine, and Cobra make aftermarket pipes for the 535. You can make alterations yourself cheaply but have to consider retaining the backpressure. I wrote a bunch of stuff on what I found via the net on it. viragotips.googlepages.com the exhaust link is at the bottom.
There is a company that sells longer forks and a head peice for the fork from the UK. Google it. I can't remember the link.
You can also get forward controls for the brake and shifter. They are on ebay, and other motorcycle parts sites sell them. The company Mapam makes them.